* feat(evals): add deterministic symbolic equivalence generated corpus
* feat(evals): add symbolic equivalence replay helpers
* feat(evals): load generated symbolic equivalence corpus
* feat(evals): emit symbolic equivalence replay manifest
* feat(symbolic): support multivariable integer polynomials
* feat(symbolic): support exact rational polynomial coefficients
* feat(symbolic): align equivalence API with multivariable normalization
* test(ADR-0131.1.B): reconcile v1 expectations to v1.B scope expansion
The v1.B refactor (univariate int → sparse multivariable Fraction) deliberately
admits multivariable polynomials and constant-denominator division. The v1
dataset and tests pinned the old refusal behavior, so the lane runner reported
wrong=4 and 10 unit tests failed.
Reconcile:
- cases.jsonl: flip sym-eq-v1-0029 ('x+y' vs 'x+1') and sym-eq-v1-0030
('x/2' vs 'x') from expected=refused to expected=not_equivalent; rename
categories to multivariable_distinct / constant_denominator_distinct;
extend provenance with adr-0131.1b:scope-expanded.
- generated_cases.py: split _refusal_cases into scope_expanded (admits)
and templates (still refused); the first two adversarial cases move to
the scope-expanded list with expected=not_equivalent.
- test_math_symbolic_normalizer.py: replace test_undefined_variable and
test_unknown_operator_division with positive scope-expansion tests +
symbolic-denominator refusal; rewrite TestPolynomialInvariants for the
new terms/variables constructor (Polynomial(terms={...}, variables=(...)))
with float-rejection and zero-coef-collapse invariants.
- test_math_symbolic_equivalence.py: TestRefused.test_empty_left reason
string matches new normalizer error; flip multivariable + constant-
denominator cases to NOT_EQUIVALENT; add symbolic-denominator-refused
case; relax canonical_a assertion in test_a_normalizes_b_refuses (engine
now zeroes both on either-side refusal).
- report.json + manifest.json: regenerated; lane PASS 185/185 wrong=0.
Lane invariants reaffirmed by the new tests: wrong==0, refusal-first for
truly out-of-scope inputs (symbolic denominator, transcendental, malformed,
negative exponent), determinism via byte-equal report.