reserve a, b, n for Nat,
  r for Real,
  f for FinSequence of REAL;
reserve p for Prime;

theorem Th4:
  for i, j, m, n being Nat st i < j & m |^ j divides n
  holds m |^ (i+1) divides n
proof
  let i, j, m, n be Nat such that
A1: i < j and
A2: m |^ j divides n;
  reconsider i,j,m as Element of NAT by ORDINAL1:def 12;
  i+1 <= j by A1,NAT_1:13;
  then m |^ (i+1) divides m |^ j by NEWTON:89;
  hence thesis by A2,NAT_D:4;
end;
