The Java uniformization classes (FundamentalPolygonUtility, CanonicalFormUtility)
rely on the *Big arbitrary-precision geometry (MathContext(50)) because products
of hyperbolic isometry generators grow exponentially and double fails to verify
the group relation ∏gᵢ = Id. Record this planning-relevant prerequisite and
resolve the contradiction in java-parity.md, which previously listed *Big as
permanently out of scope.
- CLAUDE.md: † note on the Phase-9 not-yet-ported table
- java-parity.md: *Big exception (localized high-precision substrate for 9c/10)
- phases.md: precision prerequisite as 9c sub-task + effort estimate
- design-decisions.md: new "Scalar type: double, with one localized exception"
Core flattening (Newton/energy/Eigen solver) stays double; the substrate
(cpp_dec_float_50 / mpreal) is localized to the uniformization module only.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>