fact: Definition Rpos_eqMixin := Eval hnf in [eqMixin of Rpos by <:].
imports: mathcomp(all_ssreflect) mathcomp(all_algebra vector reals normedtype) mathcomp(mathcomp_extra boolp) mathcomp(Rstruct) ssrR realType_ext Reals Lra mathcomp(lra)