Q. Consider the set N* of finite sequences of natural numbers with a denoting that sequence a is a prefix of sequence b. Then, which of the following is true? (Solved)
1. every non-empty subset of has a greatest lower bound
2. it is uncountable
3. every non-empty finite subset of has a least upper bound
4. every non-empty subset of has a least upper bound
- a. every non-empty subset of has a greatest lower bound