Here, S denotes the list [* s_1, ..., s_n *], while T denotes the list [* t_1, ..., t_m *].

S cat T : List, List -> List

The list formed by concatenating the terms of the list S with the terms of the list T, i.e. the list [* s_1, ..., s_n, t_1, ..., t_m *].

(Procedure.) Destructively concatenate the terms of the list T to S; i.e. so S becomes the list [* s_1, ..., s_n, t_1, ..., t_m *].

The list formed by adding the object x to the end of the list S, i.e. the list [* s_1, ... s_n, x *].

Append(~S, x) : List, Elt ->

(Procedure.) Destructively add the object x to the end of the list S; i.e. so S becomes the list [* s_1, ... s_n, x *].

The list formed by removing the last term of the list S, i.e. the list [* s_1, ..., s_(n - 1) *].

Prune(~S) : List ->

(Procedure.) Destructively remove the last term of the list S; i.e. so S becomes the list [* s_1, ..., s_(n - 1) *].

Seqlist(Q) : SeqEnum -> List

Given a sequence Q, construct a list whose terms are the elements of Q taken in the same order.

Tuplist(T) : Tup -> List

Given a tuple T, construct a list whose terms are the elements of T taken in the same order.