Two new π* canonicalizers extend the math substrate above
arithmetic@v1 (closed-form rationals) and logic-kernel@v1
(propositional Boolean → CNF):
algebra-symbolic@v1 (Phase 1) — symbolic-algebra domain.
sp.expand → sp.srepr canonical bytes. Polynomial identity collapses
((x+1)**2 ≡ x**2 + 2*x + 1); exponential identity collapses
(exp(a+b) ≡ exp(a)*exp(b), inherited from sp.expand's default
behavior); trigonometric identity does NOT collapse
(sin²+cos² ≢ 1). The trig surface is reserved for a future
algebra-symbolic-simplified@v1 variant that wraps sp.simplify at
unbounded CPU cost. Rejects relationals (`x > 0`) and
BooleanFunction shapes (`x & y`) via `isinstance(expr, sp.Expr)` —
sp.Symbol confusingly inherits from Boolean so the right rejection
filter is "not Expr" rather than "Boolean".
calculus-derivative@v1 (Phase 2) — calculus domain. JSON-shaped
{f, x, n} input → sp.diff → sp.expand → srepr bytes. Output is
itself a valid algebra-symbolic@v1 input so the two compose
naturally under arborist.pi_star.compose. n defaults to 1; bools
explicitly rejected (Python isinstance(True, int) is True so we
filter that explicitly).
Optional dependency: sympy ships in the new [math] extra
(pyproject.toml). Folded into [dev] so make bootstrap pulls it
transitively. An explicit `bootstrap-math` Makefile target documents
the opt-in for minimal-install users. Both modules self-guard
via `try: import sympy as sp / except ImportError: sp = None` and
only register(...) when sympy is present, so a fresh checkout
without [math] still loads arborist.pi_star without raising.
Preflight algebra route lands in
arborist.qa.query._canonical_projection_preflight between the
arithmetic and logic routes. Charset regex (_CANONICAL_ALGEBRA_RE)
allows lowercase letters + math chars; requires at least one
letter (else arithmetic wins); rejects natural-language leading
verbs via _CANONICAL_ALGEBRA_NL_LEAD_RE (4-letter minimum so
single-/two-/three-char identifiers like x, xy, sin, cos, pi
survive while "simplify (...)", "factor x...", "expand (a+b)..."
fall through). PiStarError + KeyError both fall through cleanly
so a sympy-less install just routes everything past algebra.
Bench substrate:
- bench/batteries/base.py PHASE_1_CARRIERS gains "symbolic_algebra"
- bench/fixtures/5s/syntax-algebra-symbolic-v1.jsonl (10 fixtures)
- bench/fixtures/5s/semantics-algebra-symbolic-v1.jsonl (13 fixtures
including the documented trig non-collapse + exp collapse)
- Makefile bench-5s-algebra target → 100% pass
Tests: 18 algebra-symbolic + 38 calculus-derivative unit tests +
~10 new preflight-route tests in test_canonical_projection.py. All
gate on pytest.importorskip("sympy") so a sympy-less suite stays
green. Full suite: 1369 passed / 27 skipped.
Phases 3-7 (integral, limit, series, linear-algebra,
function-sampled) remain open as future work; each lands as its
own ticket when an actual consumer surfaces.
russell@unturf.com
04f3f5d2a8