The two gaps #26 named that were never filled.
NonFiniteResult had no test at all — the name appeared in `tests/` only
inside a doc comment, and it is the sub-claim in that issue's title. It
turns out to be very much reachable, and from *finite* inputs: sigma at
1e300, beta at 1e300, sigma at 1e-300, score_sigma at 1e-300, and scores
at 1e308 all overflow inside inference, where the boundary checks cannot
see them. That matters because the failure is silent by default — NaN
fails every comparison, so a naive `step < epsilon` reads a NaN step as
converged, which is why the crate has `step_converged`/`step_is_finite`.
Pinned from outside, including that `converge_partial` does not launder a
breakdown into an `Ok`, and with a control asserting merely extreme
parameters still converge so the suite cannot pass by always failing.
Color-group disjointness was #26's fourth acceptance criterion and had
only five hand-written cases. Now a proptest over three shapes: a dense
pool where collisions force colors to multiply, a sparse one where most
events are independent, and repeated members within a single event.
Two of my first assertions were wrong about the code rather than the
reverse. A competitor named twice *within* one event is not a collision —
`color_greedy` collects each event's members into a set for that reason.
And contiguity is not a property of `color_greedy`: it holds only after
`recompute_color_groups` reorders events so each color occupies one
range. The test now asserts what is actually promised — that the reorder
is always *possible*, since the parallel sweep slices `&mut` sub-ranges
from those groups and overlapping ranges would be unsound.
Refs #26
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011hcFjNDmHXZF8URGLku5zZ
