Modeling_in_ACL2.html -- ACL2 Version 6.3

## Modeling in ACL2

Below we define mc(s,n) to be the function that single-steps n times from a given starting state, s. In Common Lisp, ``mc(s,n)'' is written `(mc s n)`.

    (defun mc (s n)                     ; To step s n times:
     (if (zp n)                         ; If n is 0
         s                              ;    then return s
         (mc (single-step s) (- n 1)))) ;    else step single-step(s)
                                                          n-1 times.

This is an example of a formal model in ACL2.