Assignment 1 - Question 3

Are we required to use identities to solve this problem or can we just loosly state the facts that lead us to a specific conclusion?

From what I read in the textbook, you need to justify your reasoning by
stating the 'rules' you used to arrive to your conclusion.

If by rules they mean identities then how do I relate them to LeftOf and Between?

If my memory serves me correctly, identities do not apply to this particular question. Identities are used to state that 2 or more labels/names refer to the
same object which in this case you are not required to do. Try to use the definitions of LeftOf and Between to show how you would arrive to your final conclusion.

[Edited] Posted this in the wrong forum.

bini is right. U need to state the laws. Either DeMorgan Or Double Negation like in Cos 113-W(computer science). by the way, thanks jeanbodermer)

When I said identities I was actually referring to the rules "elim" and "intro", I forgot that identity means = (there are way too many new terms in this subject). I still can't figure out how to apply them this question though.

In the end I just stated my reasoning without using the given "rules", something like.

The function Between(x,y,z) means that the variables x,y,z is arranged in such a way that they are either arranged horisontally, diagonaly or vertical ...... etc.

Hope that is what is expected as I can't see the rules applied here, although I do get the feeling that we basically have to prove between is transitive.

I used the definitions of Between and LeftOf and where that places each object in the grid to validate the statements.
Reanie