reserve B,C,D for Category;

theorem Th26:
  for S being Functor of C opp,B, c being Object of C holds (Obj
  /*S).c = (Obj S).(c opp)
proof
  let S be Functor of C opp,B, c be Object of C;
A1: now
    let c be Object of C;
    (/*S).(id c) = id((Obj S).(c opp)) by Lm4;
    hence ex d being Object of B st (/*S).(id c) = id d;
  end;
  (/*S).(id c) = id((Obj S).(c opp)) by Lm4;
  hence thesis by A1,CAT_1:66;
end;
