fact: Definition mnmwgt {n} (m : cmonom 'I_n) := (\sum_i m i * i.+1)%N.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap