>Hi Hilmar,
>
>>#DEFINE XOR #
>
>I did not really think of using #DEFINE but your suggestion makes the XOR available as a command instead of a function.
>
>

>? A XOR B
>

>
>Ofcourse one could just add ?A # B and keep the reader guessing...
>
>Kamal

For purposes of the puzzle, A#B is the shortest version you can get.

In actual practice, I use the #DEFINE to make the statements more readable.

But please note that #DEFINE XOR # is not necessarily the same as using the (missing) built-in XOR operator. The difference is in the order of precedence:

if A=B and C=D

The "=" operators will be evaluated first, as expected - equality has a higher precedence than logical operators.

#DEFINE XOR #
if A=B XOR C=D

The equality and the inequality have the same order of precedence, so everything will be evaluated from left to right. Probably not what the programmer expected.

Corrected version:

#DEFINE XOR #
if (A=B) XOR (C=D)