The following summary of the Expression Node syntax uses Backus-Naur Form (BNF notation). The Expression Node uses C operations, but adds the exponent operator, **.

<expr> : = <expr> <binaryoperator> <expr>
  | <unaryoperator> <expr>
  | <expr> ? <expr> : <expr>
| ( <expr >)
| <identifier>
| <const>
| <function> ( <arglist> )
<binaryoperator>: = + | - | * | / | ^ | != | == | > | < | >= | <= | && | || | & | | | ^ | **
<unaryoperator>: = + | - | ! | ~
Note To include optional items in the Expression Node syntax, use square brackets to enclose the items.