Statement
''We must appoint more subordinate officers on our office staff''. the manager said to the chairman.
Assumptions
I. Subordinates officers are available.
II. The present office staff is inefficient.

Here, the manager stresses the need to appoint more subordinate officers. It does mean that present staff is not efficient. In fact, he wants to say that work is much more then the working capacity of present staff strength. Hence, Assumption II is invalid. But Assumption I is implicit because without assuming the availability or subordinate officers, the manager would not have said so.