HOMEWORK #1: SNePS

For this HW, you might find it helpful to (re-)read Martins 2002: 172-192. Then do the following exercises from Martins 2002:

1. p. 211: #5, 6

2. p. 212: #7, 8

3. Also do the EXTRA QUESTION accompanying #6, below.

For convenience, the exercises are repeated here, using slightly different notation:

• #5: SNePS does not allow the following representation for the statement "Tweety is a bird". Explain the reason for this decision.

  Tweety

  |
  isa
  |
  V
  

  bird

• #6: Explain the differences between (a) the SNePS representation shown below for the statement "John is a man" and (b) the one from problem 5, above. Why is the representation below legal (even though Martins 2002 calls it "bad")?

  M1!

  |
  is-a-man
  |
  V
  

  John

• #6.1: *********EXTRA QUESTION*********

  Why does Martins call this "bad"? Give a better SNePS representation, and explain why it's better.

• #7: What does the following represent? (Assume that M1 and M2 are SNePS proposition-nodes.)
  (assert min 1 max 1 arg M1 arg M2)

• #8: What does the following represent? (Assume that M1,...,Mn are SNePS proposition-nodes.)
  (assert min 0 max 0 arg M1 ... arg Mn)

  (Note that in the SNePSUL renditions of 7 and 8, there is no need to include the parameters "2" and "n" that appear in the notation in Martins 2002.)