CONSTRAINT / VALIDATION
Independent validation
A validator that shares no code with the solver recomputes the objective and every affected rule from the returned placements, in every runtime.
recompute from the resultWhy it exists
A solver checking its own bookkeeping proves nothing. Recomputation by a second implementation is what turns a visualisation into evidence.
What a useful refusal looks like
The engine returns the rule that refused, the item it refused, and the measured value against the configured threshold. It also states how strongly that is backed: proven, observed, inferred, or unknown because a search limit was reached first.
See the fixtures for this rule ↗