You can prevent an expression from being evaluated by quoting it, either by preceding it with ’ or with the quote or hold) command.
Remark.
If a is a variable, then a:=quote(a) (or
a:=hold(a)) is equivalent to purge(a) (for the
sake of Maple compatibility). It returns the value of this variable
(or the hypothesis done on this variable).
Example.
Input:
or:
Output:
| 2,2+3 a |