Assignment 7 for CSCI 431

• Running Prolog

  GNU prolog (gprolog) has been installed on all Sun workstations (i.e., flat-rock, hendersonville, marshall, and brevard) as well as the Linux boxes.

  There are some example programs in /usr/local/gprolog-1.2.1/ExamplesPl on the Suns.

  The online documentation is available at the following URL:

  http://gnu-prolog.inria.fr/manual/index.html

  To get you started here are a few basics on running gprolog:

  • to run prolog type:     gprolog
  • to exit prolog type     Ctrl-D     or    halt.
  • to read a knowledge-base from a file named user type either:     [ user].     or     consult(user).

  
  

• Your Assignment: Creating A Knowledge-Base

  
  

  Create a prolog knowledge-base that can be used to reason about your family relationships.

  1. Start by adding facts about your family tree including the gender of individuals. Use two separate predicates, male/1 and female/1. For example, your program might contains the facts:

     
          male(dennis).
          male(michael).
          female(diana).
     

     If you want to include uppercase characters or embedded blanks you must enclose the name in single (not double) quotes. For example

     
          male('Ghenghis Khan').
     

  2. Also use a two-argument predicate that records the parent-child relationship. One argument represents the parent, and the other the child. It doesn't matter in which order you enter the arguments, as long as you are consistent. Often Prolog programmers adopt the convention that parent(A,B) is interpreted "A is the parent of B". For example

     
          parent(dennis, michael).
          parent(dennis, diana).
     

  3. As an intermediate check on your knowledge-base, pose a few queries:
     • Confirm a parent relationship such as parent(dennis, diana)
     • Find someone's parent such as parent(X, diana)
     • Find someone's children such as parent(dennis, X)
     • List all parent-children such as parent(X,Y)
     • You can also use compound queries to find family relationships in your knowledge-base. For example, find someone's mother with

       
            ?- parent(X, someone), female(X).
       

     If parent/2 seems to be working, you can add additional family members to get a larger knowledge-base. Remember to include the corresponding male/1 or female/1 predicate for each individual added.

  4. Now, build rules for the various family relationships, for example

     
          mother(M,C):-
            parent(M,C),
            female(M).
     

  5. Build a rule for siblings. You will probably find your rule lists an individual as his/her own sibling. You can use the built-in predicate trace to figure out why. You can fix the problem of individuals being their own siblings by using the built-in predicate that succeeds if two values are unequal, and fails if they are the same. The predicate is \=(X,Y).
  6. Use the sibling predicate to define additional rules for brothers, sisters, uncles, aunts, and cousins, for example:
     • Your parent's brother is your uncle
     • Your parent's sister is your aunt
     • Your sibling's son is your nephew
     • Your sibling's daughter is your niece
     • Your aunt/uncle's child is your first cousin
  7. Try to represent marriages in your family knowledge-base---you will run into a problem. Unlike parent/2, which has two arguments with distinct meanings, married/2 can have the arguments reversed without changing the meaning. This can be fixed by duplicating the information in a different order (there are also other ways to fix the problem):

     
          married(michael, diana).
          married(diana, michael).
     

  8. Use the new married predicate to add rules for uncles and aunts that get uncles and aunts by marriage as well as by blood. You should have two rules for each of these relationships, one for the blood case and one for the marriage case. Use trace to follow their behavior.
  9. Write a rule for grandparent/2. Use it to find both a grandparent and a grandchild.

     
          grandparent(someone, X).
          grandparent(X, someone).
     

  10. Explore writing rules for other relationships, for example
      • Your possible second cousin
      • Your possible father-in-law, mother-in-law, daughter-in-law
      • Your possible stepchild
      • Your possible half-brother
      • Your possible first cousin once removed
      • You should not marry anyone who is related to you (mother, father, grandmother, grandfather, sibling, aunt, uncle, nephew, niece, first cousin, second cousin)