reserve r,p,x for Real;
reserve n for Element of NAT;
reserve A for non empty closed_interval Subset of REAL;
reserve Z for open Subset of REAL;

theorem
  for f being PartFunc of REAL,REAL,
  A being non empty closed_interval Subset of
  REAL holds ||..(1(#)f),A..|| = ||..f,A..|| by RFUNCT_1:21;
