 reserve x for Real,
    p,k,l,m,n,s,h,i,j,k1,t,t1 for Nat,
    X for Subset of REAL;

theorem Th22:
  for m,n being natural Number st m < n+1 holds m < n or m = n
proof
  let m,n be natural Number;
  assume m<n+1;
  then m<=n by Th13;
  hence thesis by XXREAL_0:1;
end;
