fact: Definition combine_step (a b c d : R) (m n : nat) (M : 'M_(1 + m,1 + n)) (k : 'I_m) := let k' := lift 0 k in let r0 := a *: row 0 M + b *: row k' M in let rk := c *: row 0 M + d *: row k' M in \matrix_i (r0 *+ (i == 0) + rk *+ (i == k') + row i M *+ ((i != 0) && (i != k'))).
imports: HB(structures) Coq(ssreflect ssrfun ssrbool Arith.Wf_nat) mathcomp(eqtype ssrnat div seq path) mathcomp(ssralg fintype perm tuple choice generic_quotient) mathcomp(matrix bigop zmodp mxalgebra poly) stronglydiscrete