Test Log - _14_environment_diff

Tested 2026-07-20 with gpt-5.5; the baseline used low reasoning effort and the candidate used high reasoning effort where noted.

basic.py

Status: PASS

Description: Compared low- and high-reasoning policies on the same environment and rendered a valid EnvironmentDiff.

Result: Low effort: product-a 1/4 (0.25), product-d 4/4 (1.00). High effort: both rows 4/4 (1.00). The diff reported product-a improved by +0.75 and correctly marked the policy as changed.

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task_subset.py

Status: PASS

Description: Compared a high-effort task subset with a full low-effort baseline while preserving environment identity.

Result: Baseline: product-a 2/4 (0.50), product-b 3/4 (0.75). Candidate subset: product-a 4/4 (1.00). The diff reported +0.50 for the shared row and named product-b as baseline-only.

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mismatch_guard.py

Status: PASS

Description: Ran two prompt variants, then verified that the changed environment fingerprint prevents a policy-style diff.

Result: Baseline: product-a 4/4 (1.00), product-c 4/4 (1.00). Edited prompt: product-a 4/4 (1.00), product-c 3/4 (0.75). MismatchError was raised with both divergent environment fingerprints.

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