FA-16947 / Floating-point arithmetic / Member archive

Decimal fused multiply-add uses away ties in an even context · case 02

Decimal fused multiply-add uses away ties in an even context.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

Decimal fused multiply-add rounds a*b+c once in a fresh precision-limited half-even context. Inputs are decimal strings; return final decimal string and Inexact flag.

Why this case matters

An offline floating representation model isolates a reproducible arithmetic fault.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
tiny addend	`["1.01", true]`	`["1.00", true]`	Failed

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