the Simplification of the Induction Conclusion (Step 3)

Subgoal *1/2'
(IMPLIES (AND (CONSP A)
              (EQUAL (APP (APP (CDR A) B) C)
                     (APP (CDR A) (APP B C))))
         (EQUAL (APP (CONS (CAR A) (APP (CDR A) B))
                     C)
                (APP A (APP B C)))).

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