mpg-top-typ - SICStus Prolog

atom(+T) ISO: term T is an atom
atomic(+T) ISO: term T is an atom or a number
callable(+T): T is an atom or a compound term
compound(+T) ISO: T is a compound term
db_reference(+X) since release 4.1: X is a db_reference
float(+N) ISO: N is a floating-point number
ground(+T): term T is a nonvar, and all substructures are nonvar
integer(+T) ISO: term T is an integer
mutable(+X): X is a mutable term
nonvar(+T) ISO: term T is one of atom, number, compound (that is, T is instantiated)
number(+N) ISO: N is an integer or a float
simple(+T): T is not a compound term; it is either atomic or a var
var(+T) ISO: term T is a variable (that is, T is uninstantiated)