4 Pseudo-Isomorphic Tree Diversity

In an attempt to approximate the degree of isomorphism, we count the number of pseudo-isomorphic trees in the population. Pseudo-isomorphic trees are represented by the number of similar 3-tuples in the population, where a 3-tuple is defined as $<$# of terminals, # of nonterminals, depth$>$ for each individual. Two identical 3-tuples represent trees which could be isomorphic, while two non-identical 3-tuples represent trees that certainly can not be isomorphic.