
theorem Th6: :: Odd100
  for n being odd Nat st n<=2 holds n=1
proof
  let n be odd Nat such that
A1: n<=2;
  n <> 2*1;
  then n < 1+1 by A1,XXREAL_0:1;
  then
A2: n <= 1 by NAT_1:13;
  n >= 1 by ABIAN:12;
  hence thesis by A2,XXREAL_0:1;
end;
