INCOMPATIBLE

declaring that two rules should not both be enabled 
Major Section:  THEORIES


Example:
(theory-invariant (incompatible (:rewrite left-to-right)
                                (:rewrite right-to-left)))


General Form:
(incompatible rune1 rune2)
where rune1 and rune2 are two specific runes. The arguments are not evaluated. Invariant is just a macro that expands into a term that checks that not both runes are enabled. See theory-invariant.