reserve V for non empty set,
  A,B,A9,B9 for Element of V;
reserve f,f9 for Element of Funcs(V);
reserve m,m1,m2,m3,m9 for Element of Maps V;
reserve a,b for Object of Ens(V);
reserve f,g,f1,f2 for Morphism of Ens(V);
reserve C for Category,
  a,b,a9,b9,c for Object of C,
  f,g,h,f9,g9 for Morphism of C;

theorem
  Hom(C) c= V implies hom??(V,C)?-(a opp) = hom?-(V,a)
proof
  assume
A1: Hom(C) c= V;
A2: id(a opp) = id a by OPPCAT_1:71;
  thus hom??(V,C)?-(a opp)
     = (curry hom??(C)).(id a) by A1,Def26,A2
    .= hom?-(a) by Th56
    .= hom?-(V,a) by A1,Def24;
end;
