Proof of `Factorization and counting of low-rank binary matrices` (2nd statement)
groundedproofs/Lax342547Proofs/LowRankCounting.lean · lax-342547
What this proof establishes
no assumptions
Assuming the claims on the left, the claim on the right holds — checked by the archive's pipeline. Proof code is not displayed here.
Description
Choose coordinates on the image of M. Restriction from r coordinates onto those image coordinates is onto; split that surjection and express the two resulting linear maps as matrices.