2. Equivalence classes partition Definition 2. 19: A partition or quotient set of a nonempty set A is a collection II of nonempty subsets ofa such that (1) DEach element of a belongs to one of the sets in II. (2)IfAi and Ai are distinct elements of Il, then A∩A: The sets in l are called the bocks or cells of the partition. Example: Let A=a, b,c), P={a,b},c},S={a},{b},{c},T={a,b,c}, U={a,(},V={a,b},{b,},W={a,b},{a,c},(C}, nfinite2.Equivalence classes partition Definition 2.19: A partition or quotient set of a nonempty set A is a collection  of nonempty subsets of A such that (1)Each element of A belongs to one of the sets in . (2)If Ai and Aj are distinct elements of , then Ai∩Aj=. The sets in  are called the bocks or cells of the partition. Example: Let A={a,b,c}, P={{a,b},{c}},S={{a},{b},{c}},T={{a,b,c}}, U={{a},{c}},V={{a,b},{b,c}},W={{a,b},{a,c},{c}}, infinite