reserve r, s, t, g for Real,

          r3, r1, r2, q3, p3 for Real;
reserve T for TopStruct,
  f for RealMap of T;

theorem Th10:
  f is continuous implies r3+f is continuous
proof
  assume
A1: f is continuous;
  let X be Subset of REAL;
  assume X is closed;
  then
A2: -r3++X is closed by MEASURE6:53;
  (r3+f)"X = f"(-r3++X) by MEASURE6:70;
  hence thesis by A1,A2;
end;
