Phase 1b — algebra-symbolic-simplified@v1
==========================================
arborist/pi_star/algebra_symbolic_simplified.py — full-simplify
variant of the Phase-1 expand-only sibling. Closes the trig
identity gap left open at end of Phase 1: sin(x)**2 + cos(x)**2
now collapses to 1, tan(x)*cos(x) to sin(x), exp(log(x)) to x.
Recipe is sp.expand(sp.simplify(expr)) — the follow-up expand
after simplify is load-bearing. simplify alone is non-canonical
for polynomials: it leaves (x+1)**2 in factored form while
collapsing x**2 + 2*x + 1 to expanded form, so two algebraically
equivalent inputs would emit different bytes. Composing with
expand picks one canonical polynomial shape and preserves the
equivalence-class invariant.
Cost: 1-360 ms typical on common trig/exp inputs; pathological
inputs unbounded. No in-π* timeout (the calling pipeline owns
that budget). Operators opt in by registry key — the fast Phase-1
sibling stays the default for callers that only need polynomial
canonicalization.
22 unit tests; all gate on pytest.importorskip("sympy").
Phase 3 — calculus-integral@v1
==============================
arborist/pi_star/calculus_integral.py — symbolic integration with
thread-timeout fallback. JSON-shaped {f, x, limits?,
timeout_seconds?} input. Two output paths:
1. Closed form: sp.srepr(sp.expand(integrate_result)) — same
recipe as algebra-symbolic@v1 so the output is itself a valid
algebra-symbolic input and composes naturally.
2. Unevaluated: b"unevaluated:" + sp.srepr(<Integral>). Prefix
lets callers tell "no closed form" from "input invalid"
without re-parsing the canonical form.
Timeout discipline: ThreadPoolExecutor(max_workers=1) +
future.result(timeout=...). On TimeoutError, synthesize the same
unevaluated sentinel SymPy itself would emit, so timeout +
no-closed-form converge to the same bytes for the same input.
Default 30 s; per-call override via timeout_seconds. Python
threads can't be killed cleanly — a timed-out worker leaks until
SymPy returns. Documented as the cost of the discipline.
Coverage: ∫x dx = x²/2, ∫sin(x) dx = -cos(x), ∫_{0}^{π} sin(x)
dx = 2, ∫_{-∞}^{∞} exp(-x²) dx = √π, exp(x)/log(x) →
unevaluated sentinel. 31 unit tests including a monkeypatch
deterministic timeout test (sleep-mocked SymPy so the timeout
path doesn't depend on any specific input being slow on every
CI runner).
Open #000031 — surface-ingest cited textbooks
=============================================
Design-only ticket. Closes the warrant gap left open at the end
of #000029: today every claim-pack record caps at
ANCHOR-WARRANTED because source_reference is a string field, not
a Merkle-bound proof. Ingesting the cited textbooks as surfaces
+ computing per-claim derivations.proof_blob lets the four-rung
ladder promote them to EVIDENCE-WARRANTED.
License gating: PD sources (Hilbert, Newton, Kolmogorov,
Łukasiewicz, Aristotle) form the green-light scope. Mendelson +
Enderton are proprietary and stay yellow-light pending fox's
explicit decision (purchased single copy / library license / PD
substitute via Hilbert-Ackermann 1928).
Two follow-up tickets reserved: textbook-fetch pipeline +
chunk-resolution layer (mapping source_reference strings to
specific spans within ingested textbooks; the bridge that lets
proof_blob be computed).
Test counts: 153 tests for the work in this commit (algebra
+ algebra-simplified + calculus-derivative + calculus-integral
+ preflight). All pi_star + canonical_projection tests pass
under .venv pytest.
russell@unturf.com
5257f9a8f3