Hey guys, having trouble with the following question.
Let A = {1,2,3,4},
a) how many relations are there on A?
My answer: = =
b) How many equivalent relations are there on A?
My answer: Im not sure about this one. Any help?
Before I answer please answer this.
Does you textbook/instructor really use the notation for the cross product of with itself?
The almost standard notation is .
For the help. There is a one-to-one correspondence between the partitions of the set and the equivalence relations on the set.
You want to find the fourth Bell number.