Prolog - recursing down family tree

Question

I am trying to write a Prolog program that will print out the male successors of British Royalty in order. My attempt so far:

son(elizabeth, charles).
son(charle         


        

Answer 1

Your rule set looks good to me, it's giving you the right results, it's just printing them as it deduces them, which makes the order seem incorrect. Work through the results on paper and you will likely get a similar result.