Boolean values
You can use the Boolean variables true and false in GeoGebra. Just type, for example, a = true or
b = false into the Input Bar and press the Enter key. With Boolean variables you
can e.g. define the conditional visibility of an object.
Check Box and Arrow Keys
Free Boolean variables can be displayed as check boxes in the 
Graphics View (see tool
Check Box
Tool). After selecting a Boolean variable in the 
Algebra View you can use the arrow keys to change the value of
the Boolean variable (see Manual Animation).
|
You may also use Boolean variables like numbers (value 0 or 1). This allows you to use a checkbox as the dynamic speed
of an animated slider allowing you to start and stop the animation. In this case, the animation button is only shown in
the |
Operations
You can use the following operations for Boolean variables and conditions in GeoGebra by either selecting them from the list next to the Input Bar or by entering them using the keyboard:
| Operation | List | Keyboard | Example | Object types |
|---|---|---|---|---|
Equal |
≟ |
== |
a ≟ b or a == b |
numbers, points, lines, conics, functions (needs CAS), planes, a, b |
Not equal |
≠ |
!= |
a ≠ b or a != b |
numbers, points, lines, conics, functions (needs CAS), planes a, b |
Less than |
< |
a < b |
numbers a, b |
|
Greater than |
> |
a > b |
numbers a, b |
|
Less or equal than |
≤ |
⇐ |
a ≤ b or a ⇐ b |
numbers a, b |
Greater or equal than |
≥ |
>= |
a ≥ b or a >= b |
numbers a, b |
And |
∧ |
&& |
a ∧ b or a && b |
booleans a, b |
Or |
∨ |
|| |
a ∨ b or a || b |
booleans a, b |
Not |
¬ |
! |
¬a or !a |
boolean a |
Exclusive or |
Alt+ |
a ⊕ b |
booleans a, b |
|
Implication |
→ |
→ |
a → b |
booleans a, b |
Parallel |
∥ |
a ∥ b |
lines a, b |
|
Perpendicular |
⊥ |
a ⊥ b |
lines a, b |
|
Belongs to |
∈ |
a ∈ list1 |
number a, list of numbers list1 |
|
Subset |
⊆ |
list1 ⊆ list2 |
lists list1 and list2 |
|
Proper subset |
⊂ |
list1 ⊂ list2 |
lists list1 and list2 |