Implement the rules required to simulate a computer that supports the instructions: move, add, decrement, jump, and jump_on_zero.

Details:

• This problem has been analyzed in terms of 19 rules and 6 predicates. Each rule corresponds to one clause. The file GivenRules.pp lists these 19 rules and provides implementation in PicoProlog of 11 of them. The remaining eight, rules 2, 5, 9, 10, 13, 17, 18, and 19, are left for you to implement.
• Three test simulations are provided to exercise the rule implementation:
  • Simulate1.pp
  • Simulate2.pp
  • Simulate3.pp
  These are also available on gaul in the directory: /gaul/s1/usr/faculty/webber/CS342/Homework6 .
• Again, cut ! is not to be used. PicoProlog features that are relevant to this homework include integer, plus, nil, and :.

Handin Requirements

• What to hand in
  • You will need to handin your source file Hmwk6.pp (the other source files you may not change and you may not use any additional source files, so there is no need to hand in any other source files).
  • On the hardcopy version only, it is required that three test runs be shown. This involves printing the results of using script to capture the results of the following output sequence:

        cat Hmwk6.pp
        cat GivenRules.pp
        cat Simulate1.pp
        pprolog Hmwk6.pp GivenRules.pp Simulate1.pp
           answer(X).
        cat Simulate2.pp
        pprolog Hmwk6.pp GivenRules.pp Simulate2.pp
           answer(X).
        cat Simulate3.pp
        pprolog Hmwk6.pp GivenRules.pp Simulate3.pp
           answer(X).
    

    NOTE: after the answer(X). query, each answer returned should be responded to with a carriage return. To exit pprolog, one types the end of file character, which on gaul is usually control-D. The test data files can be found on gaul in: /gaul/s1/usr/faculty/webber/CS342/Homework6 .
  • It is perfectly fine to use your home printers as long as they are readable.
  • The hardcopy version must be in an 8.5x11 envelope if it is being handed in in the locker. If it is being handed in in class, it is ok if it is just stabled together (2 stables) or in a report folder (clasped). Loose pages or pages held together only be a paperclip are too easy to get mixed up together. Envelops that are not 8.5x11 make the pile of assignments difficult to sort through and should not be used. Your name should appear clearly on the outside cover of whatever you are handing in, as well as on each page.
  • For online handin, use CS342HandinFromGaul as was done for Homework 1.
• When to hand it in: the process is the same as for the second homework.

Reference:

Chapters 1, 2, and 3 of the Spivey text on Prolog are sufficient for this assignment. For plus and integer, it is useful to take a look at Section 14.2 of the text.

Sample Run:

This is an example of what it looks like to run this assignment on a sample program that moves the contents of the first location in memory to the eight location and then quits.

brown[205]: cat x.pp

   answer(X) :- simulate(
                   state(1, 
                         3:nil, 

                         instruction(move,1,8): 
                         instruction(jump,0,0): 
                         nil), 

                   X).
brown[206]:  pprolog Hmwk6.pp GivenRules.pp x.pp
Welcome to picoProlog
Reading Hmwk6.pp
Reading GivenRules.pp
Reading x.pp

# :- answer(X).

X = 3:0:0:0:0:0:0:3:nil ? 

no

# :- ^D

Hints:

• Given a coding style where the missing rules look much like the provided rules, but the commenting is restricted to simply identifying which clause corresponds to which rule, my solution was 54 lines long (159 words, 2143 characters).
• In interpreting the missing rules, you are also trying to make something that fits in with the given rules. It is useful to read through the given rules and their interpretations to get a feeling for how the English is being translated.
• In working with Prolog, coming up with the rules is generally a bigger issue than encoding the rules. Thus, in addition to paying attention to the details of translation, it is also worthwhile looking at how the rule sets relate to the original problems.
• In working with things like change_memory, don't forget that it is possible to test them directly without having to get the rest of the stuff to work. For example,

  pprolog Hmwk6.pp GivenRules.pp x.pp
  Welcome to picoProlog
  Reading Hmwk6.pp
  Reading GivenRules.pp
  Reading x.pp
  
  # :- change_memory(3, 2:nil, 7, X).
  
  X = 2:0:7:nil ? 
  
  no
  

  lets us see that when we try to change the 3rd memory location to 7 in a memory list of just one cell that has the value 2, the right new memory list is produced (with a 0 second element and the first element unchanged).