fact: Definition nds_value n c := let k := n %/5 in let i := n %% 5 in if n <= 7 then c n else if (i== 0) then (c 5) ^ k else if (i==1) then (c 6) * (c 5) ^ k.-1 else if (i==2) then (c 6) ^ 2 * (c 5) ^ k.-2 else if (i==3) then if(k== 1) then (c 4) ^ 2 else if(k==2) then (c 4) ^ 2 * (c 5) else (c 6)^3 * (c 5) ^ (k-3) else (c 4) * (c 5) ^ k.
imports: Coq(BinNat) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div)