Suppose we have the following open statements on x:
$\ S(x) $ means that "x is a student"
$\ P(x) $ means that "x likes pizza"
$\ L(x,y) $ means that "x loves y"
$\ K(x,y) $ means that "x knows y"
How would we write the following statements?
- All students like pizza
- Everyone has somebody who loves them
- Only students like pizza
- All love is mutual
- Everyone likes pizza or everyone is a student
- I know someone who knows someone who knows Ariana Grande
- Everyone who knows Ariana Grande loves her
Whats mainly confusing me is the separation of these variables. Some with 1 and the other "connectors" with 2. How would I properly answer these?
I'll just do 2 as an example ... Hopefully that'll help you with the others.
OK, so you need a universal for 'everyone', but you also an existential for the 'someone' who loves them. So:
$$\forall x \exists y L(y,x)$$