theorem Th21:
  for F being Element of Funcs(REAL*,REAL*), f being Element of
  REAL*,n,i be Element of NAT holds (repeat F).0 .f = f
proof
  let F be Element of Funcs(REAL*,REAL*), f be Element of REAL*,n,i be Element
  of NAT;
  thus (repeat F).0 .f = (id (REAL*)).f by Def2
    .= f;
end;
