Combined condition
Two or more conditions can be logically connected to form a combined condition.
Syntax
condition-1  {AND}  condition-2
             {OR }
The condition to be combined can be any of the following:
A simple-condition
A negated simple-condition
A combined condition
A negated combined condition (that is, the NOT logical operator followed by a combined condition enclosed in parentheses)
When relation-conditions are written consecutively, any relation-condition after the first can be abbreviated in one of two ways:
Omission of the subject
Omission of the subject and relational operator