# Expressions in properties

A valid expression for a property value is a sequence of operands, operators, and parentheses that the runtime system can evaluate as a single value.

The RTL Expression language used in Report Writer closely follows the Java™ syntax for expressions and evaluation semantics.

- Arithmetic formulas can be used.
- Conditional expressions allow you to express IF/ELSE statements.
- Genero BDL variables can be used.
- Functions from the Reporting API can be used.

Press the** fx** button to open the Expression Editing Window.