### NFIX

coerce to a natural number
Major Section: ACL2-BUILT-INS

`Nfix`

simply returns any natural number argument unchanged,
returning `0`

on an argument that is not a natural number. Also
see ifix, see rfix, see realfix, and see fix for
analogous functions that coerce to an integer, a rational number, a
real, and a number, respectively.

`Nfix`

has a guard of `t`

.

To see the ACL2 definition of this function, see pf.