I'm writing a program in Prolog : Write a predicate cau_neg(Numbers,Sum) that sums the squares of only the negative numbers in a list of numbers.

NOTE: "!" , ";" , "... -> ... ; ..." and cuts are not allowed to be used here.

example:

?- cau_neg([-1,-3,9,37,6,-2,22], Sum). Sum = 14

It computes (-1) * (-1) + (-3) * (-3) + (-2) * (-2).

And think about how the predicate should behave on the empty list fail or is there a reasonable value that Sum can be bound to??

Thank you so much!