The Expression Node syntax is summarized below using Backus-Naur Form (BNF notation). Square brackets enclose optional items.
<expr> : = <expr> <binaryoperator> <expr>
| <unaryoperator> <expr>
| <expr> ? <expr> : <expr>
| ( <expr>)
| <identifier>
| <const>
| <function> ( <arglist> )
<binaryoperator>:= + | - | * | / | ^ | != | = = | > | < | >= | <= | && | || | & | | | ^ | **
<unaryoperator>: = + | - | ! | ~