An expression can be combined with one or more other expressions. The rules language supports the use of arithmetic operators and the concatenation operator (||) to combine expressions.
The arithmetic operators allow four types of operands: count, quantity, date, and typeless. The only operands allowed for unary - and unary + are count, quantity, and typeless. For a complete description of arithmetic operators and their behavior, refer to
What are the Arithmetic Operators?.
The rules language uses a double vertical bar (||) as the concatenation operator. Concatenation is valid between any two semantic data types and always has a result with semantic type string. For its syntax, the result follows these rules in order:
Operators within an expression conform to conventional notation and obey the precedence that follows. Exponentiation has highest precedence and addition, subtraction, and string-concatenation have the same lowest precedence. In cases where more than one operator has the same precedence, such as addition and string-concatenation, the operators are evaluated strictly from left to right, unless explicitly overridden using parentheses.