fact: CoInductive edivn_spec_left (m d : nat)(qr : nat * nat) : Type := EdivnSpec_left of m = (fst qr) * d + (snd qr) & (d > 0) ==> (snd qr < d) : edivn_spec_left m d qr.
imports: mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat div)