Flawed_Induction_Candidates_in_App_Example.html -- ACL2 Version 6.3

## Flawed Induction Candidates in App Example

Induction on a is unflawed: every occurrence of a in the conjecture

    (equal (app (app a b) c)
           (app a (app b c)))

is in a position being recursively decomposed!

Now look at the occurrences of `b`. The first (shown in bold below) is in a position that is held constant in the recursion of `(app a b)`. It would be ``bad'' to induct on `b` here.

    (equal (app (app a b) c)
           (app a (app b c)))