Sequences, Ranges, Sets, and Lists of Expressions

A sequence is made from a finite number of expressions that are
separated by commas.  For instance, "x" is a sequence with one item, and
"x, y" is a sequence of two items.  The special symbol "NULL" is used to
denote the empty sequence.  A sequence is a valid type, "exprseq", so
whattype and type can be used on it.  The arguments that you pass to a
function are an example of a sequence.

Sets and lists are also Maple types.  A set is just a sequence of items
between "{" and "}" symbols; a list is a sequence of items between "["
and "]" symbols.  Their Maple type names are "set" and "list".

To access particular items of sequences, sets, and lists all you have to
do is subscript them:

> w0 := a1, a2, a3:
> w0[1];
a1
> w1 := {a1, a2, a3};
w1 := {a3, a2, a1}
> w1[2];
a2
> w2 := [a1,a2,a3];
w2 := [a1, a2, a3]
> w2[1..2];
a1, a2

The last example uses a "range".  A range is valid Maple type and is
used to describe a range of values.  Unlike sequences, sets, and lists,
you can not subscript a range.

There are a number of operations that work on sequences, sets, and
lists.  See the Maple help sections on their type names for more
information.