Internal hygiene + future-proofing. No serving path, no new capability — the 15-case
reader is structurally cleaner and the projection no longer recovers meaning by
re-parsing a string.
- New generate/quantitative_expr.py: a typed Expr IR (Literal/Symbol/Add/Sub/SumOf) with
to_canonical_string (BYTE-IDENTICAL to the legacy "ref + delta" / "ref - delta" / "a + b"
format), dependencies, operation_kind, and to_relation (the structured projection).
- The reader builds the Expr per equation as the SOURCE OF MEANING; rhs_canonical,
dependencies, and operation_kind are all DERIVED from it (BoundEquation stays a string —
the binding-graph's deliberate decoupling layer is untouched). QuantComprehension carries
the IR as equation_exprs.
- to_relational_metric reads the IR via to_relation — the rhs_canonical string-reparse is
GONE. An unhandled equation shape refuses (None).
- The dead _rhs string builder is removed.
Gates held: relational_metric answer lane 15/15 wrong=0; setup-oracle 15/15 setup_wrong=0;
malformed-target refusals intact; realize-binding-graph + architectural invariants green
(95). rhs_canonical is byte-identical, so the binding-graph + downstream hashes are
unchanged. No model change.
This is the foundation PR-5's R1 frames build on — structured equations, not string parsing
— and only after independent R1 gold is hand-authored.
