 
 
 
16.8  Built-Ins and Attributed Variables
- 
free(?Term)
- 
This type-checking predicate succeeds iff its argument is an
ordinary free variable, it fails if it is an attributed variable.
 
 
- meta(?Term)
- 
This type-checking predicate succeeds iff its argument is an attributed variable.
For other type testing predicates an attributed variable behaves like a variable.
 
 
