fact: Definition oprod2_comm_P4 x y := exists z gamma c1 c2, [/\ cnfp_nz z, \0o <o oexp z \0c, ordinalp gamma & [/\ natp c1, natp c2, x = cnf_val z, cnf_degree z = gamma *o c1 & y = oopow (gamma *o c2) *o x]].
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)