A relation is a subset of the cartesian product V x W, so a set of tuples {(v1, w1), (v2, w2), …} with each v[i] an element of V and each w[i] an element of W.
The sets V and W can be finit, countable infinite (like the set of natural numbers) or uncountable infinite (like the set R of real numbers).
A few examples:
Let V be the set of all people and W be the set of all cars. Then we can make a Venn diagram with arrows starting in V and ending in W that express ownership. A person can own 0, 1, 2, … cars. So this is not a function.
Answers & Comments
Step-by-step explanation:
A relation is a subset of the cartesian product V x W, so a set of tuples {(v1, w1), (v2, w2), …} with each v[i] an element of V and each w[i] an element of W.
The sets V and W can be finit, countable infinite (like the set of natural numbers) or uncountable infinite (like the set R of real numbers).
A few examples:
Let V be the set of all people and W be the set of all cars. Then we can make a Venn diagram with arrows starting in V and ending in W that express ownership. A person can own 0, 1, 2, … cars. So this is not a function.