hex-dev is the development monorepo where new Hex sublibraries are
incubated before they are split out for release. hex is the released
aggregate repo; it depends on released split libraries at exact Lake
revisions.
The currently pinned upstream split repos for hex are:
hex-matrixhex-matrix-mathlibhex-gram-schmidthex-gram-schmidt-mathlibhex-lllhex-lll-mathlib
Treat this as the current pinned set, not a permanent exhaustive list:
more sublibraries may be released from hex-dev later. Computational
libraries are Mathlib-free; *-mathlib repos are the Mathlib bridge
layers and should contain correspondence proofs and Mathlib-facing APIs.