FA-343 / Integer arithmetic / Member archive

A positive-only tie rule rounds negative halves toward zero · case 03

Exact midpoint values receive even rounding or asymmetric rounding instead of the required away-from-zero result.

Member previewVariant 3 · 3 implementations · 9 checks per implementation

Case contract

Round numerator/denominator to the nearest integer, with exact ties away from zero. Inputs are integers and denominator must be positive; invalid denominators return None. No decimal parsing or floating-point conversion occurs.

Why this case matters

Quantizers and fixed-point protocols need an explicit signed tie rule. The failure here is a rounding-policy mismatch, separate from binary representation error when parsing decimals.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
positive half after even integer	`6`	`7`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.