Order of Evaluation lists the rules governing which part of the expression SAS evaluates first. The rules also list how a compound expression that contains more than one operator from the same group is evaluated. Symbols lists the symbols that you use to request the comparisons, operations, and calculations. Mnemonic Equivalent lists alternate forms of the symbol. In some cases, such as when your keyboard does not support special symbols, you should use the alternate form.
Definition defines the symbol.
Example provides an example of how to use the symbol or mnemonic equivalent in a SAS expression. A plus sign is a prefix operator only when it appears at the beginning of an expression or when it is immediately preceded by a left parenthesis or another operator. A minus sign is a prefix operator only when it appears at the beginning of an expression or when it is immediately preceded by a left parenthesis or another operator. This is because Group I operators are evaluated from right to left. Group V operators are comparison operators.