Note that the required relational characters "<" , ">", and "=" are not underlined, to avoid confusion with other symbols
such as '>' (greater or equal to).
Relation tests can be made only between:
- Two index-names. The result is the same as if the corresponding occurrence numbers were compared.
- An index-name and a numeric data item or numeric literal. The occurrence number that corresponds to the value of the index-name
is compared to the data item or literal.
- An index data item and an index-name or another index data item. The actual values are compared without conversion.
- An index-name can be compared with an arithmetic expression. The occurrence number that corresponds to the value of the index-name
is compared to the computed value of the expression.
- The result of the comparison of an index data item with any data item or literal not specified above is undefined.