- fx+? N1 N2procedure
- fx-? N1 N2procedure
- fx*? N1 N2procedure
- fx/? N1 N2procedure
These procedures behave similarly to their standard counterparts with the exception that #f is returned if an argument is not a fixnum or the result of the operation overflows.
Chaining of such procedures is well-defined and causes the overflow error to be propagated.