6.4.2 List predicates

Function: pair? obj

[R5RS] Returns #t if obj is a pair, #f otherwise.

Function: null? obj

[R5RS] Returns #t if obj is an empty list, #f otherwise.

Function: list? obj

[R5RS] Returns #t if obj is a proper list, #f otherwise. This function returns #f if obj is a dotted or circular list.

See also proper-list?, circular-list? and dotted-list? in 10.2.2 List predicates.