Write a program that does calcuations (addition and multiplication) where the interface looks like English, for example

     How much is the product of 1, 2, 3, 4, and 5?

Details:

• The given part can be found in Hmwk7.Given.pp It is also available on gaul in the directory: /gaul/s1/usr/faculty/webber/CS342/Homework7 .

  For a competing implementation that taking a different approach, see 3001 by Arthur C. Clarke: Talk to HAL 9000.

• The subset of English that we are handling is described in Hmwk7.Given.pp as:

  1] hal_9000(Sentence, Response) is the start of construction of the 
     program for the HAL 9000 computer.  This first step is meant to 
     compute numeric responses to simple English questions.  Samples 
     of the kinds of questions we are trying to handle are:
         How much is 3?
         How much is the sum of 3 and 4?
         How much is the sum of 3, 4, and 5?
         How much is the product of 12 and 5?
         How much is the product of 1, 2, 3, 4, and 5?
         How much is the sum of 1, 2, the product of 3 and 4, and 5?
     The above six questions are wellformed under the following rules.
     Each question begins with "How much is" and ends with a question
     mark. In general wherever a number could occur a sum or product 
     could also occur.  You can sum or product two or more numbers.  
     If two numbers, then they are separated by `and'.  If more than two
     numbers, then each number before the `and' is followed by a comma.
  
     Anything that is not well formed under the above is not well formed
     and an attempt to parse it will fail.
  

• You are defining the predicate parse which is used by the predicate hal_9000 to convert the result of the predicate tokenize into something that can be processed by the predicate evaluate. See the documentation of these predicates in Hmwk7.Given.pp.
• The given part includes the test data. The test data is evaluated by the predicates test_hal and test_hal_some_more.
• Again, cut is not to be used.

Handin Requirements

• What to hand in
  • You will need to handin your source file Hmwk7.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 two test runs be shown. This involves printing the results of using script to capture the results of the following output sequence:

        cat Hmwk7.pp
        cat Hmwk7.GivenRules.pp
        pprolog Hmwk7.pp Hmwk7.GivenRules.pp 
          test_hal.
          test_hal_some_more.
    

  • 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 10 and 11 of the Spivey text on Prolog are sufficient for this assignment.

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[221]: pprolog Hmwk7.Given.pp Hmwk7.pp  
Welcome to picoProlog
Reading Hmwk7.Given.pp
Reading Hmwk7.pp

# :- test_hal.
"In response to: How much is 3?"
hal_says(3)
"In response to: How much is the sum of 3 and 4?"
hal_says(7)
"In response to: How much is the sum of 3, 4, and 5?"
hal_says(12)
"In response to: How much is the product of 12 and 5?"
hal_says(60)
"In response to: How much is the product of 1, 2, 3, 4, and 5?"
hal_says(120)
"In response to: How much is the sum of 1, and 2?"
"In response to: How much is the sum of 1, 2, the product of 3 and 4, and 5?"
hal_says(20)

no

# :- ^D

Hints:

• This task took me 10 clauses. These clauses took 112 words (2452 characters) spread across 38 lines. When I added comments, the file grew to 95 lines, 330 words, and 4963 characters.
• Chapter 10 presents a slow simple way to parse and a more complicated quicker way to parse. I opted for the slow simple way.
• 13 predicates are defined in Hmwk7.Given.pp. What you are doing is defining the predicate parse, which is used by the predicate hal_9000.
• A first step toward writing the prolog rules is to take the descriptioon of the subset of English being used and convert it into grammar rules. My analysis had 10 grammar rules (which corresponded to my 10 clauses). The non-terminals I used were:
  • question
  • number expression
  • sum number list
  • product number list
• Not everything has to be done in the grammar. For example, instead of worrying about making the grammar not handle

    How much is the sum of 3, and 4 ?
  

  I let the grammar accept the above, but used a flag to let the prolog rules detect that the list `3,' was too short for there to be a `,'.
• In addition to parsing the question, you are also building the corresponding parse tree. This parse tree must be of the form that is handled by the evaluate predicate in Hmwk7.Given.pp (which looks quite a bit like value in Section 11.1 of the text).