  Grammar inference deals with determining (preferable simple) models/grammars
consistent with a set of observations. There is a large body of research on
grammar inference within the theory of formal languages. However, there is
surprisingly little known on grammar inference for graph grammars. In this
paper we take a further step in this direction and work within the framework of
node label controlled (NLC) graph grammars. Specifically, we characterize,
given a set of disjoint and isomorphic subgraphs of a graph $G$, whether or not
there is a NLC graph grammar rule which can generate these subgraphs to obtain
$G$. This generalizes previous results by assuming that the set of isomorphic
subgraphs is disjoint instead of non-touching. This leads naturally to consider
the more involved ``non-confluent'' graph grammar rules.
