fact: Definition ereal_inf_reality_subdef (xnz : KnownSign.nullity) (xr : KnownSign.reality) := (if KnownSign.wider_reality >=0 xr then KnownSign.Real >=0 else >=<0)%snum_sign.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(fsbigop cardinality set_interval) reals signed topology constructive_ereal