Def 7 Suppose M is a point collection. The statement taht P is a boundary point of M means P is a point and R is a region containing P, then R contains a point of M and a point not in M.

Prob 5 No point of a region is a boundary point.

Prob 6 Every region has a boundary point.

Prob 7 If P is a limit point of the point set M must P belong to M?

1) S₁ and S₂ are subsets of numbers.

2)  S₁ and S₂ have no number in common.

3) Each point in S₁ is to the left of each point in S₂.

4)The union of S₁ and S₂ is the real numbers R.

5) Either S₁ has a right most number or S₂ has a left most number.

Prob 8 There is a positive number t such that t*t=3.

Prob 9 If M is a number collection and B is a number such that each number in M is less than B than there is a number L such that no number in M exceeds L and if a is a number less than L, than there is a number in M greater than a.

Def 8 The statement that t is a graph means G is a point collection.

Def 9 The statement that f is a function meeans f is a graph such that no two points of f has the same first number.