fact: Definition GAr B m n := #|[set t:{set 'I_B.+1} | (Zeck_svalp t == m) && (Zeck_sval t == n) ]|.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path fintype div bigop binomial) mathcomp(prime finset ssralg ssrnum ssrint)