Example of class merges. “E” represents class equivalency. (A) Classes and axioms present in target and sources prior to merge. Note that previously Uberon had no classes for the metapterygoid or its joints. (B) Classes present in target post-merge. TAO and AAO quadrate classes have been merged into the taxonomically equivalent Uberon class, and two new classes are added to Uberon, lifted from TAO. As a separate procedure, all joint axioms are "flipped", with the joints being defined by the elements they are connected to.