fact: Definition self_sub (K : numDomainType) (V W : normedModType K) (f : V -> W) (x : V * V) : W := f x.1 - f x.2.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrint ssrnum finmap matrix) mathcomp(rat interval zmodp vector fieldext falgebra) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality set_interval Rstruct) ereal reals signed topology prodnormedzmodule