Illustration of the abbreviation:
A few illustration of the abbreviation are given below:
Illustration:
The compound condition
AMOUNT GREATER THAN 499 AND AMOUNT LESS THAN 1000
can be abbreviated to
AMOUNT GREATER THAN 499 AND LESS THAN 1000
Here, the second appearance of the general subject AMOUNT has been absent.
Illustration:
The compound condition
CARD-CODE = 3 OR CARD-CODE = 5 OR CARD-CODE = 7
may be abbreviated to
CARD-CODE = 3 OR 5 OR 7
In this, the subjects as well as the relational conditions in the given compound condition are similar. Accordingly, the second and third appearances of the subject and the relational condition have been absent.
The consecutives relational conditions which are being considered for the abbreviation may also hold the word NOT. In this situation the interpretation of the abbreviated condition can become ambiguous. To solve the ambiguity the rule below has been recommended in the ANS I standard. The term NOT preceding a relational operator in an abbreviated condition is considered part of the relational operator. Or else, NOT is considered to be a logical operator negating the condition preceded by it. The illustration below can help to understand this rule.
Illustration:
The condition
AGE LESS THAN 30 AND NOT LESS THAN 20 OR 40
is interpreted to be the abbreviation of a compound condition AGE LESS THAN 30 AND AGE NOT LESS THAN 20 OR AGE NOT LESS THAN 40
This is because the NOT precedes the relational operator LESS THAN in the abbreviated condition and as such it is interpreted to be a section of the relational operator NOT LESS THAN.