17: Relations Last updated Save as PDF Page ID 83488 Jeremy Sylvestre University of Alberta Augustana 17.1: Basics Relation (working definition): a rule which assigns to some elements of a set A several elements from a set B 17.2: Operations on Relations Union (of relations R1,R2 ): the relation where a(R1∪R2)b means that at least one of aR1b or aR2b is true 17.3: Properties of Relations Here we list some important properties a relation R on a set A can have. 17.4: Graphing Relations Recall that if R is a relation on a set A, then formally R is a subset A×A. In other words, R is a collection of ordered pairs of elements from A. 17.5: Activities 17.6: Exercises