Is this not logical?

Ian Goddard (igoddard@erols.com)
Mon, 23 Feb 1998 11:23:05 -0500

If A implies B to a degree equal to
that in which B implies A, then A = B.

IF (A => B) = (A <= B)
THEN A = B

IF A <=> B
THEN A = B

ERGO: "<=>" = "="