The rules of logical syntax must follow of themselves, if we only know how every single sign signifies. An expression prescribes a computation that produces a value or variable. Syntactically, an expression is either an operand, or an operation applied to arguments, which are themselves expressions.
Operands are identifiers, literals, or types.
An expression is evaluated by recursively evaluating its arguments and performing the operation. The order of argument evaluation is undefined for all operations except AND and OR . The following topics are discussed below.