beginner question

From: shoko (shoko2004_at_hotmail.com)
Date: 10/09/04 

Date: 9 Oct 2004 07:19:40 -0700

hi
in the following grid:
a b c d
e f g h
i j k l

each slot is defined:
slot(a,none,none,b,e).
slot(b,a,none,c,f).
slot(c,b,none,d,g).
slot(d,c,none,none,h).
slot(e,none,a,f,i).
slot(f,e,b,g,j).
slot(g,f,c,h,k).
slot(h,g,d,none,l).
slot(i,none,e,j,none).
slot(j,i,f,k,none).
slot(k,j,g,l,none).
slot(l,k,h,none,none).

i need to defined diagonal rule
meaning b and l are in the same diagonal
diagonal (X,Y)

and a higher rule
meaning d is higher then f
higher(X,Y)

please help i have tried several ways and i can't get to the right solution

i am stuck here

thanks alot the despret one.............