parse mult. comparisons, like (0 < $x <= $y < 256)

[rurban]

into a series of RELOP's with log && in-between. Idea by David Nielson, perl6 has it.

if (0 < $x < 256) { ...} => if ((0 < $x) && ($x < 256)) { ...}

term RELOP term RELOP term =>
   $$ = AND (RELOP(1, 3), RELOP(3, 5))

The only problem for this simple feature is that the middle op $3 must be cloned in the 2nd part of AND, because it cannot be re-used. Wrong next and parent links.
Saving it to an intermediate result scalar would also be possible.