# nth_tail/4

### Module: builtins

`deleteNth/3`

— deletes the Nth element of a list

`change_nth/3`

— destructively changes the Nth element of a list

`subst_nth/4`

— non-destructively changes the Nth element of a list

`nth_tail/4`

— returns the nth head and tail of a list

`at_most_n/3`

— returns initial segment of list of length =< N

`get_list_tail/3`

— returns the tail of a list determined by an element

`sublist/4`

— extracts a sublist from a list

`last/2`

— returns last element of a list

`delete_1st/3`

— deletes the left-most entry of Item in List

`nonmember/2`

— tests for the failure of membership

## FORMS

`deleteNth(N, List, Remainder)`

`change_nth(N, List, NewItem)`

`subst_nth(N, List, NewItem, NewList)`

`nth_tail(N, List, Head, Tail)`

`at_most_n(List, N, Head)`

`get_list_tail(List, Item, Tail)`

`sublist(List,Start,Length,Result)`

`last(List, Item)`

`delete_1st(List, Item, Result)`

`nonmember(List, Item)`

## DESCRIPTION

** deleteNth/3** If N is a non-negative integer and List is a list, then Remainder
is the result of deleting the Nth element of List.
This predicate numbers the list beginning with 1.

** change_nth/3** If N is a non-negative integer, List is list, and NewItem is any
non-var object, destructively changes the Nth element of List to become
NewItem. This predicate numbers the list beginning with 0.

** subst_nth/4** If N is a non-negative integer, List is list, and NewItem is any
non-var object, NewList is the result of non-destructively changing
the Nth element of List to become NewItem.
This predicate numbers the list beginning with 0.

** nth_tail/4** If List is a list and N is a non-negative integer, then Head is
the portion of List up to and including the Nth element,
and tail is the portion of List from the Nth element to the end.

** at_most_n/3** If List is a list and N is a non-negative integer, Head is the
longest initial segment of List with length =< N.

** get_list_tail/3** If List is a list and Item is any object, Tail is the portion
of List extending from the leftmost occurrence of Item in List
to the end of List. Fails if Item does not belong to List.

** sublist/4** If List is an arbitrary list, Result is the sublist of
length Length, beginning at position Start in List.

** last/2** If List is a non-empty list, Item is the last (right-most) element
of List.

** delete_1st/3** If Item occurs on List, deletes the left-most entry of Item on
List, returning in Result the tail of List beginning at that entry.
Fails if Item is not on List.

** nonmember/2** Succeeds iff member(List, Item) fails