Coral 66 Language Reference Manual: For mission-critical applications
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Conditional Expressions

A conditional expression has the form

        Conditionalexpression ::=
    IF
        Condition
        THEN
        Expression
        ELSE
        Expression

with the usual interpretation.

Conditions

A condition is made up of arithmetic comparisons connected by Boolean operators OR and AND, of which AND is the more tightly binding. The permitted arithmetic comparisons are less than, less than or equal to, equal to, greater than or equal to, greater than, and not equal to. The syntax rules are

          Condition ::=
    Condition
          OR
          Subcondition
          Subcondition

          Subcondition ::=
    Subcondition
          AND
          Comparison
          Comparison

          Comparison ::=
    Simpleexpression
          Comparator
          Simpleexpression

          Comparator ::=
    <
    <=
    =
    >=
    >
    <>

The Boolean operators have their usual meanings, the OR being inclusive. Conditions are evaluated from left to right only as far as is necessary to determine their truth or falsity.