fact: CoInductive nonneg_spec (R : numDomainType) (x : R) : R -> bool -> Type := | IsNonneg (p : {nonneg R}) : nonneg_spec x (p%:num) true.
imports: HB(structures) Coq(ssreflect ssrfun ssrbool) mathcomp(ssrnat eqtype choice order ssralg ssrnum ssrint) mathcomp(mathcomp_extra)