is_list/1¶

"is_list( ?List " )

is_list(+ List)*

List must be a list, that is, it must be bound to a true list.

The predicate causes an instantiation exception if List is unbound, and fails if Term is bound but not to a list.

True when List is a proper list. That is, List is bound to the empty list (nil) or a term with functor '.' and arity 2.