(Solved): 3. Use the well-ordering principle as stated to prove that any nonempty set C of integers none of w ...

3. Use the well-ordering principle as stated to prove that any nonempty set C of integers none of which is less than a specified integer \( a \) has a least element. Hint: Consider the set \( D \) of all integers of the form \( c-a+1 \) where \( c \) is an element of \( C \).