FAILURE MAP
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FA-88996 / Digital logic simulation / Open access

Fanout branch fault applied to every reader of the stem · case 01

A branch fault is detected by vectors that only propagate through other fanout branches.

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

ROOT CAUSE

Branch faults force the net on every gate input that reads it, turning them into stem faults.

VERIFIED REPAIR

Force the value only on the pin of the named reader gate.

Unsuccessful approach: Forcing the reader gate output instead of its input pin models a different 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] = sv if (p == net and pin is None) else vec[p]
        for out, op, ins in gates:
            bits = [sv if i == net 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, 0]][['n1', 'n4', 0, None]]Failed
input fault masked downstream[['c', 'n5', 1, 1]][['c', 'n5', 1, 1]]Passed

SHA-256 / d9d0b75377d742a9b5a38a0fc84838307da7c8dde685d1942e576168b78b680f

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) else vec[p]
        for out, op, ins in gates:
            bits = [val[i] for i in ins]
            v = sv if pin == out else 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, 0]][['n1', 'n4', 1, 5]]Failed
fanout branch fault into n2[['n1', 'n2', 0, 0]][['n1', 'n2', 0, 1]]Failed
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, 0]][['c', 'n5', 1, 1]]Failed

SHA-256 / c1c34a5cff3ede16e34c3bacb043b19af6e02f88544d206037db70b990b44b82

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 2026-09-29T14:51:13.327836+00:00.

Case digest / 4f916b8f37d867d3048ff954cb090ef8cac0c0322aa4c8b8d220f0537d3f4a13