fact: Definition pinvmx : 'M_(n, m) := invmx row_ebase *m pid_mx mxrank *m invmx col_ebase.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype finfun bigop finset fingroup perm order) mathcomp(div prime binomial ssralg finalg zmodp matrix)