Proof of `Rank of a tensor killed in two quotient spaces` (3rd statement)
groundedproofs/Lax342547Proofs/QuotientRank.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
The kernel of the left quotient is its subspace. The right quotient's dual image is its annihilator, whose codimension is the subspace dimension.