Consistently Adding Primitive Recursive Definitions in ACL2

In [2, 3], P. Manolios and J Moore show that a tail recursive defining equation for a new function can always be consistently added to ACL2. This is done by “constructing” a function that satisfies the proposed tail recursive defining equation. Their construction is extended to many primitive recursive defining equations. This extends the known recursive schemes that can be consistently introduced into ACL2’s logic. Exactly what is meant by “primitive recursive” and the exact restrictions placed on the definitions are explained below.