### 4.6.10 Unassigning variables: VARS purge DelVar del restart rm_a_z rm_all_vars

The VARS() command will list the variables to which you have assigned values or assumptions. If you begin by entering

a := 1

and

anothervar := 2

then

VARS()

will return

[a, anothervar]

The purge command will clear the values and assumptions you make on variables. To clear the values and assumptions on a, for example, you can enter
Input:

purge(a)

For TI compatibility, you can also enter
Input:

DelVar a

and for Python compatibility, you can also enter Output:

del a

To clear the values and assumptions you have made on all variables you can use the

restart

or

rm_all_vars()

command. The command rm_a_z will clear the values and assumptions of the variables with single lowercase letter names. If you have variables names A,B,a,b,myvar, then after
Input:

rm_a_z()

you will only have the variables named A,B,myvar.