Homework for February 14, 2019: Due TUESDAY February 19.

1.  Recall the definitions of reflexive, symmetric and transitive relations.
	Recall that a relation is a set of ordered pairs.
    Let A = {1,2,3}. 
	For each of the following, create digraphs and the resultant set of order pairs
	that show the following:

    (a) an example of a binary relation R1 over A that is
        reflexive but not symmetric, but not transitive.

    (b) provide an example of a binary relation R2 over A that is
        not reflexive and not transitive, and not symmetric.

    (c) provide an example of a binary relation R3 over A that is
        not reflexive and is symmetric and transitive.

         
2.  Complete the answers from page 6 on the 08-RelationsDeepDive lecture slide. 
	It will help to draw the digraphs.
	
3.  Determine the relations for a, b in the set of integers and the mathematical
	relation R: >, i.e "greater than"

4. 	Determine the relations for a, b in the set of integers and the mathematical
	relation R: a*b = 0