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

theorem :: TOPREAL6'5
  a <> 0 implies a / (a / b) = b
proof
  assume
A1: a <> 0;
  thus a/(a/b) = a * (a/b)" by XCMPLX_0:def 9
    .= a * (b/a) by Lm7
    .= a*b/a by Lm8
    .= a/a*b by Lm8
    .= 1 * b by A1,Lm5
    .= b;
end;
