Found by the N6e grounding-audit (HEAD 55b59fc), probe-verified:
def m1 := [map dbl '[1 2 3]] → "Expression is not a valid type" on a well-formed List Int — the driver def-path is-type gate (driver.rkt:1549 is-type/err) rejects it, while the identical expression works in eval position.def r2 := [reduce int+ 0 '[1 2 3]] → multiplicity error at the checkQ-top gate (driver.rkt:1591-1594), also eval-green.
So def-RHS × trait-generic collections is broken for everything, independent of wildcards/op-values (the Numerics N6e scope). Root cause undiagnosed — WHY is-type rejects List Int in the def path needs its own investigation (suspect: the def pipeline's inferred-type handling of applied-tycon results or residual metas at the gate).
Repro: probes in the N6e audit transcript (wf_091b4433); both errors reproduce verbatim at HEAD.
Context: docs/tracking/2026-06-30_NUMERICS_TRACK_STAGE3_DESIGN.md §9d D-N6.6 (N6e mini-design, "filed as separate bugs").
Found by the N6e grounding-audit (HEAD 55b59fc), probe-verified:
def m1 := [map dbl '[1 2 3]]→ "Expression is not a valid type" on a well-formedList Int— the driver def-path is-type gate (driver.rkt:1549is-type/err) rejects it, while the identical expression works in eval position.def r2 := [reduce int+ 0 '[1 2 3]]→ multiplicity error at the checkQ-top gate (driver.rkt:1591-1594), also eval-green.So def-RHS × trait-generic collections is broken for everything, independent of wildcards/op-values (the Numerics N6e scope). Root cause undiagnosed — WHY is-type rejects
List Intin the def path needs its own investigation (suspect: the def pipeline's inferred-type handling of applied-tycon results or residual metas at the gate).Repro: probes in the N6e audit transcript (
wf_091b4433); both errors reproduce verbatim at HEAD.Context: docs/tracking/2026-06-30_NUMERICS_TRACK_STAGE3_DESIGN.md §9d D-N6.6 (N6e mini-design, "filed as separate bugs").