TOPS-20 PASCAL Language Manual - Bitsavers

EXPRESSIONS
The set operators (+, *, -, =, , =) require both operands
to be set values. The TN operator, however, requires a set expression
as its second operand and a scalar expression of the associated base
type as its first operand, for example:
The value of this expression is TRUE, because 2*3 evaluates to 6,
which is a member of the set rl •. 10].
3.1.5 Precedence of Operators
The operators in an expression establish the order in which PASCAL
evaluates the expression. Table 1-6 lists the order of precedence of
the operators, from highest to lowest.
Table 3-h:
Precedence of Operators
Operators
Precedence
NOT
Highest
**
* I, DIV, MOD, REM, AND
* OR
, =, IN Lowest
PASCAL evaluates operators of equal precedence (such as + and -) from
left to right. You must use parentheses for correct evaluation when
you combine relational operators, for example:
A (= X AND B (= Y
Without parentheses, PASCAL attempts to evaluate this expression as
A