Prolog N-Queens Diagonal Check

I am brand new to prolog and am trying to design an algorithm checkDiagonal based off

eightQueens(Board) :- permutation([1,2,3,4,5,6,7,8], Board), checkDiagonal(Board).

the algorithm is supposed to check whether or not a permutation of the board creates a situation where a queen can take another DIAGONALLY. I understand the concept of how each column (A,B,C, etc.) has horizontal co-ordinates 1-8, but I am not sure how to use this knowledge to develop the function.

I have looked at the answer GuyCoder posted here: Understanding CLP(FD) Prolog code of N-queens problem

and although it was extremely extensive, a lot of it went over my head due to my lack of experience.

Any assistance would be much appreciated.