In: Advanced Math
Let A be a subset of the integers. (a) Write a careful definition (using quantifiers) for the term smallest element of A. (b) Let E be the set of even integers; that is E = {x ∈ Z : 2|x}. Prove by contradiction that E has no smallest element. (c) Prove that if A ⊆ Z has a smallest element, then it must be unique.