Proof that Akers' algorithm for locally exhaustive testing gives minimum test sets of combinational circuits with up to four outputs

In this paper, we prove that Akers' test generation algorithm for the locally exhaustive testing gives a minimum test set (MLTS) for every combinational circuit (CUT) with up to four outputs. That is, we clarify that Akers' test pattern generator can generate an MLTS for such CUT.<
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