while studying First Order Logic some of my results are a little different from the results in the book.
Can you please tell me if they are equivalement or why mine does not work?
Since we dont have the sybols, the following will be used:
* Universal = A
* Existential = E
* Negation = Not
"Jack owns a dog"
Ex dog(x) AND owns(jack,x)
"Jack doesn't own a dog"
Not Ex dot(x) ANd owns(jack, x)
"Every dog owner is an animal lover"
Ax Ey dog(y) AND onws(x,y) => animallover(x)
Ax (Ey Dog(y) AND Owns(x,y))=>AnimalLover(x)
- This is almost equal... are the () significant?
"No animal lover kills an animal."
Not Ex Ay animal_lover(x) AND animal(y) AND kills(x, animal)
Ax animal_lover(x) => Ay animal(y) => not kills(x,y)
- This differs that I just use ANDs and no => (implication)
when should we use SKOLEM functions and when should we use skolem constants?