Expressions
An expression is any statement that has a value. The simplest form of expression is a literal, however expressions can be as complex as any legal combination of operators, conditions, functions, and values you can imagine.
Expression components
Literal values
A literal value is a value written exactly as it is meant to be interpreted, such as the character literal 'my value'. For information about literals, see Data types.
Operators
Operators are symbols that tell the script interpreter to perform arithmetic, string, comparison, or logical evaluation of the specified values:
Operator type in order of precedence  Operators in order of precedence  Examples 

Parenthesis 

(5 + 3) * 2 
Unary 

v_truth = NOT (3 < 2) 
Arithmetic 
Note Multiplicative operators have equal precedence with each other and evaluate from left to right. Additive operators have equal precedence with each other and evaluate from left to right. 
1 + 5  3 * 2 
String  + concatenates  "This is" + " my script" 
Comparative 
Note Comparative operators have equal precedence with each other and evaluate from left to right. 
IF amount <> 100 
Binary logical 

IF amount > 5 AND amount < 10 
Functions
Expressions are evaluated using the values returned by functions. Functions execute with the highest precedence of any expression component. For more information about functions, see Functions.
Example expressions
Evaluates to 6
(2 + (3  2)) * 2
Evaluates to true
((2 + (3  2)) * 2) > ROOT(9,0)
Evaluates to 'ACLScript tutorial'
'AC' + 'LScri' + 'pt ' + 'tutorial'