reserve i, i1, i2, j, k for Nat,
  r, s for Real;

theorem Th4:
  for j,k being Nat holds 0<k & k<=j & k mod j=0 implies k=j
proof
  let j,k be Nat;
  assume that
A1: 0<k and
A2: k<=j and
A3: k mod j=0;
  k >= j by A1,A3,NAT_D:24;
  hence thesis by A2,XXREAL_0:1;
end;
