Primary objective of this lecture is to present on Notation. A system of symbols used to represent special things. Example: In mathematical notation “∞” means “infinity”. A mathematical notation is a writing system used for recording concepts in mathematics. The notation uses symbols or symbolic expressions which are intended to have a precise semantic meaning. Assume that A is the set of even natural numbers between 1 and 10 inclusive. There are 5 elements in set A: A = {2,4,6,8,10}. Another way to say this is #(A) = 5.