FAILURE MAP
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FA-88991 / Digital logic simulation / Open access

Stuck-at faults on primary inputs never injected · case 01

Faults on primary inputs are reported as undetected by every vector.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Primary input values are copied from the vector without applying a stem fault on that input.

VERIFIED REPAIR

Force a primary input to the stuck value when the fault targets it as a stem.

Unsuccessful approach: Injecting only stuck-at-0 input faults still misses every stuck-at-1 input fault.

Case contract

Input [pis, gates, pos, vectors, faults]. Gates [out, op, ins] are topologically ordered (and/or/nand/nor/not). A fault [net, None, v] is a stem stuck-at on a primary input or gate output; [net, reader, v] is a branch fault that forces only the pin of gate 'reader' that reads 'net'. A fault is detected by a vector when any primary output differs from the fault-free circuit. Return [net, reader, v, first detecting vector index or None] per fault.

Why this case matters

Fault simulators grade test sets; stem/branch distinction and output comparison determine reported coverage.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(*args):
    pis, gates, pos, vectors, faults = args
    def ev(op, bits):
        if op == 'and': return int(all(bits))
        if op == 'or': return int(any(bits))
        if op == 'nand': return 1 - int(all(bits))
        if op == 'nor': return 1 - int(any(bits))
        return 1 - bits[0]
    def sim(vec, fault):
        net, pin, sv = fault if fault else (None, None, None)
        val = {}
        for p in pis:
            val[p] = vec[p]
        for out, op, ins in gates:
            bits = [sv if (i == net and pin == out) else val[i] for i in ins]
            v = ev(op, bits)
            val[out] = sv if (out == net and pin is None) else v
        return [val[o] for o in pos]
    res = []
    for f in faults:
        first = None
        for idx, vec in enumerate(vectors):
            if sim(vec, f) != sim(vec, None):
                first = idx
                break
        res.append([f[0], f[1], f[2], first])
    return res
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 1]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 5]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 2]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 4]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 2]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 1], ['n3', None, 0, 3]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 3]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 1]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 4]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 6]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 2]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 2]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 5]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 5]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 1]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 3]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 6]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, None]])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
primary input stuck-at-1[['a', None, 1, None]][['a', None, 1, 1]]Failed
primary input stuck-at-0[['b', None, 0, None]][['b', None, 0, 1]]Failed
fanout branch fault into n4[['n1', 'n4', 1, 5]][['n1', 'n4', 1, 5]]Passed
fanout branch fault into n2[['n1', 'n2', 0, 1]][['n1', 'n2', 0, 1]]Passed
fault visible only at the second output[['n4', None, 1, 0]][['n4', None, 1, 0]]Passed
fault visible only at the first output[['n2', None, 0, 0]][['n2', None, 0, 0]]Passed
stem fault on internal net[['n1', None, 0, 0], ['n3', None, 0, 2]][['n1', None, 0, 0], ['n3', None, 0, 2]]Passed
branch fault masked on its reader[['n1', 'n4', 0, None]][['n1', 'n4', 0, None]]Passed
input fault masked downstream[['c', 'n5', 1, 1]][['c', 'n5', 1, 1]]Passed

SHA-256 / 41a4af9739c4cfb95b35b26ef1c03e8b9be0bd2768803f98755e7058f8aff809

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(*args):
    pis, gates, pos, vectors, faults = args
    def ev(op, bits):
        if op == 'and': return int(all(bits))
        if op == 'or': return int(any(bits))
        if op == 'nand': return 1 - int(all(bits))
        if op == 'nor': return 1 - int(any(bits))
        return 1 - bits[0]
    def sim(vec, fault):
        net, pin, sv = fault if fault else (None, None, None)
        val = {}
        for p in pis:
            val[p] = sv if (p == net and pin is None and sv == 0) else vec[p]
        for out, op, ins in gates:
            bits = [sv if (i == net and pin == out) else val[i] for i in ins]
            v = ev(op, bits)
            val[out] = sv if (out == net and pin is None) else v
        return [val[o] for o in pos]
    res = []
    for f in faults:
        first = None
        for idx, vec in enumerate(vectors):
            if sim(vec, f) != sim(vec, None):
                first = idx
                break
        res.append([f[0], f[1], f[2], first])
    return res
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 1]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 5]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 2]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 4]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 2]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 1], ['n3', None, 0, 3]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 3]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 1]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 4]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 6]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 2]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 2]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 5]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 5]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 1]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 3]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 6]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, None]])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
primary input stuck-at-1[['a', None, 1, None]][['a', None, 1, 1]]Failed
primary input stuck-at-0[['b', None, 0, 1]][['b', None, 0, 1]]Passed
fanout branch fault into n4[['n1', 'n4', 1, 5]][['n1', 'n4', 1, 5]]Passed
fanout branch fault into n2[['n1', 'n2', 0, 1]][['n1', 'n2', 0, 1]]Passed
fault visible only at the second output[['n4', None, 1, 0]][['n4', None, 1, 0]]Passed
fault visible only at the first output[['n2', None, 0, 0]][['n2', None, 0, 0]]Passed
stem fault on internal net[['n1', None, 0, 0], ['n3', None, 0, 2]][['n1', None, 0, 0], ['n3', None, 0, 2]]Passed
branch fault masked on its reader[['n1', 'n4', 0, None]][['n1', 'n4', 0, None]]Passed
input fault masked downstream[['c', 'n5', 1, 1]][['c', 'n5', 1, 1]]Passed

SHA-256 / c47ed6ef786e71dfa6be399c72387510d50aa1f9243548ad6101521a0ea38835

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(*args):
    pis, gates, pos, vectors, faults = args
    def ev(op, bits):
        if op == 'and': return int(all(bits))
        if op == 'or': return int(any(bits))
        if op == 'nand': return 1 - int(all(bits))
        if op == 'nor': return 1 - int(any(bits))
        return 1 - bits[0]
    def sim(vec, fault):
        net, pin, sv = fault if fault else (None, None, None)
        val = {}
        for p in pis:
            val[p] = sv if (p == net and pin is None) else vec[p]
        for out, op, ins in gates:
            bits = [sv if (i == net and pin == out) else val[i] for i in ins]
            v = ev(op, bits)
            val[out] = sv if (out == net and pin is None) else v
        return [val[o] for o in pos]
    res = []
    for f in faults:
        first = None
        for idx, vec in enumerate(vectors):
            if sim(vec, f) != sim(vec, None):
                first = idx
                break
        res.append([f[0], f[1], f[2], first])
    return res
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 1]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 5]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 2]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 4]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 2]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 1], ['n3', None, 0, 3]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 0]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 0]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 3]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 1]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 1]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 4]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, 1]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['a', None, 1]]], [['a', None, 1, 6]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['b', None, 0]]], [['b', None, 0, 2]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 2]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 0]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 5]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 0}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['c', 'n5', 1]]], [['c', 'n5', 1, 0]])], [('primary input stuck-at-1', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['a', None, 1]]], [['a', None, 1, 5]]), ('primary input stuck-at-0', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['b', None, 0]]], [['b', None, 0, 1]]), ('fanout branch fault into n4', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n4', 1]]], [['n1', 'n4', 1, 1]]), ('fanout branch fault into n2', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n1', 'n2', 0]]], [['n1', 'n2', 0, 3]]), ('fault visible only at the second output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n4', None, 1]]], [['n4', None, 1, 0]]), ('fault visible only at the first output', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 1, 'b': 0, 'c': 0}], [['n2', None, 0]]], [['n2', None, 0, 0]]), ('stem fault on internal net', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 0, 'b': 1, 'c': 1}, {'a': 0, 'b': 1, 'c': 0}, {'a': 0, 'b': 0, 'c': 1}, {'a': 0, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}, {'a': 1, 'b': 0, 'c': 1}], [['n1', None, 0], ['n3', None, 0]]], [['n1', None, 0, 0], ['n3', None, 0, 6]]), ('branch fault masked on its reader', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 0}, {'a': 1, 'b': 1, 'c': 1}], [['n1', 'n4', 0]]], [['n1', 'n4', 0, None]]), ('input fault masked downstream', [['a', 'b', 'c'], [['n1', 'nand', ['a', 'b']], ['n2', 'or', ['n1', 'c']], ['n3', 'not', ['n1']], ['n4', 'and', ['n1', 'b']], ['n5', 'nor', ['n3', 'c']]], ['n2', 'n4', 'n5'], [{'a': 1, 'b': 0, 'c': 1}, {'a': 1, 'b': 1, 'c': 0}], [['c', 'n5', 1]]], [['c', 'n5', 1, None]])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
primary input stuck-at-1[['a', None, 1, 1]][['a', None, 1, 1]]Passed
primary input stuck-at-0[['b', None, 0, 1]][['b', None, 0, 1]]Passed
fanout branch fault into n4[['n1', 'n4', 1, 5]][['n1', 'n4', 1, 5]]Passed
fanout branch fault into n2[['n1', 'n2', 0, 1]][['n1', 'n2', 0, 1]]Passed
fault visible only at the second output[['n4', None, 1, 0]][['n4', None, 1, 0]]Passed
fault visible only at the first output[['n2', None, 0, 0]][['n2', None, 0, 0]]Passed
stem fault on internal net[['n1', None, 0, 0], ['n3', None, 0, 2]][['n1', None, 0, 0], ['n3', None, 0, 2]]Passed
branch fault masked on its reader[['n1', 'n4', 0, None]][['n1', 'n4', 0, None]]Passed
input fault masked downstream[['c', 'n5', 1, 1]][['c', 'n5', 1, 1]]Passed

SHA-256 / 65680fcd1e607799f33ecdd104f73ca7cc0258ed1afe4a4508d48db8a65b9aa9

Verification & scope

A deterministic bounded teaching model of one simulator rule set; the contract is stipulated and is not a claim of conformance to any HDL standard or commercial simulator. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:51:13.325117+00:00.

Case digest / 7563861738365686354ee01d10b6c796d2ac024cccdfe0a1b91504097cfaf606