inverse functions in acl2(r)
ACL2(r) supports the definition of real-valued functions. In this paper, we introduce a theory of inverse functions into ACL2(r). The theory is developed in stages, from an abstract description of inverse functions, to a still abstract but more tractable treatment of the inverse of continuous functions. A macro is introduced to simplify the introduction of concrete inverse functions. We illustrate the approach by defining some inverse functions in ACL2, including the square root, natural logarithm, inverse sine, and inverse cosine functions.
inverse functions acl2 mechanized math nonstandard analysis intermediate value theorem