Feb 6 , Week 4

We starting proofs this week , we learn how to construct the basic structure of a proof . Assume > conclude , then assume again >conclude , each assumption must match toward the its own conclusion. Eventually we will reach the "tricky" part in the middle of somewhere . Examples such as n^2 odd => n odd proof by contrapositive ,  n even => n^2 even , that sometime its easier to proof in the other direction. Basically, writing a proof is like solving math puzzle where you know the solution picture but you have find the pieces to match up.