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Previous studies have shown that conditional discrimination training procedures involving identity matching to complex samples can produce emergent arbitrary relations. Identity-based training with complex stimuli therefore may be a valuable procedure for efficiently generating large networks of stimulus relations. The present study was an attempt to increase the yield of emergent relations from identity-based procedures by (a) including an extra (cross-modal) stimulus among the elements of the complex sample that was not implicated directly in the experimental contingencies and (b) including this extra stimulus in overlapping stimulus sets to promote the merger of separately trained classes. Identity-based relations were taught in the format of ABCD-X, in which Stimuli A, B, and C were visual symbols presented as a compound, D was an auditory stimulus presented simultaneously with the ABC compound, and X was a correct comparison stimulus identical to A, B, or C. Four 4-member stimulus classes emerged from this training, and pairs of classes sharing an auditory stimulus (0) subsequently merged to form two 7 -member classes. The training of 12 identity-based relations produced 72 untrained arbitrary relations. This yield rivals that expected from stimulus equivalence procedures involving arbitrary-matching training and thus provides encouragement for the extension of identity-based procedures in the field of stimulus equivalence.