# Conditional expressionsΒΆ

Conditional expressions evaluate and return boolean (TRUE and FALSE) expressions for conditional and looping expressions.
They can contain conditional operators, **and** and **or**.

Examples of conditional expressions:

```
; The branch is taken if SomeVar is TRUE, *or* both the following things are true:
; SomeOtherVar is TRUE and AnotherVar is FALSE.
(if (or SomeVar (and SomeOtherVar (not AnotherVar)))
(= x 10)
else
(= x 20)
)
; The or and and operators can take multiple arguments. In this case, if either SomeVar,
; AnotherVar or AThirdVar are TRUE, the branch will be taken.
(if (or SomeVar AnotherVar AThirdVar)
(= x 10)
)
; Sometimes it can be useful to place the condition terms on more than one line
; Here the branch is taken if the ego is on green, its x coordinate is less than 100,
; and it has the radio transmitter in its inventory.
(if (and
(& ctlGREEN (gEgo onControl:))
(< 100 (gEgo x?))
(gEgo has: INV_TRANSMITTER)
)
(Print "The transmitter begins to beep")
)
```