existsExtended
inline fun <T> Node.existsExtended(noinline sel: (T) -> Boolean? = null, noinline mustSatisfy: (T) -> QueryTree<Boolean>): QueryTree<Boolean>
Evaluates if the conditions specified in mustSatisfy hold for at least one node in the graph.
The optional argument sel can be used to filter nodes which are considered during the evaluation. This filter should be rather simple in most cases since its evaluation is not part of the resulting reasoning chain.