Logical Proof oppgave, prøv og løs !

[OPL]

Given the statement: Ax (Cube(x) -> Ay (Dodec(y) -> FrontOf(x, y)))

Prove: Ax Ay ((Cube(x) & Dodec(y)) -> FrontOf(x, y))

 

Now, to make this possible consider yourself to be in what has been described to me as a Tarski's World (named after a guy, I think a logician but not sure named Tarski ). In this world, things are either cubes, tetrahedrons, or dodecahedrons. They can be small, medium, or large. And they are on a grid such that nothing can occupy the same square. Functions like FrontOf, BackOf, LeftOf, etc apply in cases even when they are not directly in front, back, left, etc of each other.

 

Also, since I don't know the symbols, If you see Ax or Ex, they are the universal and existential quantifiers (Ax meaning for all x and Ex meaning for some x).

 

This is a relatively simple proof, but you have to know how to do it so it may take some work

 

Noen som greier å løse dette her ?

Endret 14. oktober 2007 av OPL