reserve a, b, c, d, e for Complex;

theorem :: REAL_2'39
  b <> 0 & b / a = b implies a = 1
proof
  assume that
A1: b<>0 and
A2: b/a=b;
  a <> 0 by A1,A2,Th49;
  then b=b*a by A2,Lm3;
  hence thesis by A1,Th7;
end;
