This filter rejects Trees which have unary or binary productions
which the given parser does not contain.
One situation where this happens often is when grammar compaction
is turned on; this can often result in a Tree where there is no
BinaryRule which could explicitely create a particular node, but
the Tree is still valid. However, for various applications of the
DVParser, this kind of Tree is useless. A good way to eliminate
most of this kind of tree is to make sure the parser is trained
with -compactGrammar 0.