VMS Help DCL Tips, Expression  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    When you specify an expression, DCL evaluates values based on
    the operations specified in the expression. The values can be
    integers or character strings.

    Some expression operators are conventional mathematical
    symbols, for example, plus sign (+). Others specify logical
    and comparison operations, and consist of letters preceded and
    followed by periods; for example, .EQS. Operators are assigned a
    precedence that determines their order of evaluation. You can use
    parentheses to override this order.

    For additional information on specifying expressions, refer to
    the OpenVMS User's Manual.

1 - Arithmetic

 The operator with the highest precedence in an expression is
 evaluated first. Following this, the next highest operator is
 evaluated, and so on. Operators with the same precedence are
 evaluated from left to right, as they appear in the expression.

    Operator  Precedence Description

    *         6          Arithmetic multiplication
    /         6          Arithmetic division
    +         5          Arithmetic plus
    -         5          Arithmetic minus
    .EQ.      4          Arithmetic equal
    .GE.      4          Arithmetic greater than or equal
    .GT.      4          Arithmetic greater than
    .LE.      4          Arithmetic less than or equal
    .LT.      4          Arithmetic less than
    .NE.      4          Arithmetic not equal
    .NOT.     3          Logical NOT
    .AND.     2          Logical AND
    .OR.      1          Logical OR

2 - String

    The operator with the highest precedence in an expression is
    evaluated first. Following this, the next highest operator
    precedence is evaluated, and so on. Operators with the same
    precedence are evaluated from left to right, as they appear in
    the expression.

    Operator Precedence Description

    +        5         String concatenation
    -        5         String reduction
    .EQS.    4         String equal
    .GES.    4         String greater than or equal
    .GTS.    4         String greater than
    .LES.    4         String less than or equal
    .LTS.    4         String less than
    .NES.    4         String not equal