Fail to match if node matches anything on the list.
fails can be used with an _xWILD rule element on the right-hand side of a rule. fail is an alternate form for fails.
# This rule collects everything up to
an _endofpar or a subsequent _par, and reduces that
# set of one or more nodes to _par (which could be short for paragraph).
_par <- _xWILD [plus fails=(_endofpar _par)] @@
match, excepts, Phrase Element Modifiers.