CSE 472/572, Spring 2002

HW #9: KNOWLEDGE REPRESENTATION II: SNePS

Here is the syntax and semantics for some generic SNePS case frames.

EnglishexamplelogicSNePS example
x is a YJohn is a computer scientist Y(x)
or:
x \epsilon Y
       M     
      / \
     /   \
  member class
   /       \
  /         \
 |           |
 V           V
 x           Y
        M
       / \
      /   \
   member class
    /       \
   /         \
  |           |
  V           V
 John      computer
          scientist
x is YJohn is rich Y(x)
       M
      / \
     /   \
 object property
   /       \
  /         \
 |           |
 V           V
 x           Y
        M
       / \
      /   \
  object property
    /       \
   /         \
  |           |
  V           V
 John        rich
x stands in the relation R to y John is taller than Ann R(x,y)
        M
       /|\
      / | \
     /  |  \
  arg1 rel arg2
   /    |    \
  /     |     \
 |      |      |
 V      V      V
 x      R      y
         M
        /|\
       / | \
      /  |  \
   arg1 rel arg2
    /    |    \
   /     |     \
  |      |      |
  V      V      V
 John  taller  Ann
        than      
(This generalizes to:)R(t1,...,tn)
        M
       /|\
      / | \
     /  |  \
    /   |   \
  rel arg1..argn
  /     |     \
 /      |  ..  \
|       |       |
V       V       V
R       t1  ..  tn
All As are BsAll dogs are animals \forall x [A(x) => B(x)]
                  M
                 /| \
                / |  \
               /  |   \
              /   |    \
            ant   |     cq
            /     |      \
           /      |       \
          |     forall     |
          V       |        V
         P1       |       P2
         /\       |       /\
        /  \      |      /  \
       /    \     |     /    \
   class  member  |  member  class
     /        \   |   /        \
    /          \  |  /          \
   /            \ | /            \
  /              \|/              \
 |                |                |
 V                V                V
 A                x                B
[dog]                       [animal]

Here's an extended example, with 2 corresponding, but slightly different, SNePS networks (one with ``default'' arc labels, as above, and one with more descriptive arc labels):

John bought a book from Mary

                M1----time--->past
               /|\
              / | \
             / / \ \
            /  | |  \
           /  /   \  \
          /   |   |   \
         /   /     \   \
       rel  arg1  arg2 arg3
       /    /       \    \
      /     |       |     \
     /     /         \     \
    /      |         |      \
   /      /           \      \
  |      |             |      |
  V      V             V      V
 buy    John           B1    Mary
                       ^
                       |
                       |
                     member
                       |
                       |
                      M2---class--->book





                M2----time--->past
               / \
              / | \
             / / \ \
            /  | |  \
           /  /   \  \
          /   |   |   \
         /   /     \   \
       act agent object from
       /    /       \    \
      /     |       |     \
     /     /         \     \
    /      |         |      \
   /      /           \      \
  |      |             |      |
  V      V             V      V
 buy    John           B1    Mary
                       ^
                       |
                       |
                     member
                       |
                       |
                      M2---class--->book

Now, translate each of the following sentences (from HW #8) into SNePS. Be sure to give your syntax and semantics:

DUE: AT THE START OF LECTURE: WEDNESDAY, MAY 1



Copyright © 2002 by William J. Rapaport (rapaport@cse.buffalo.edu)
file: 572/S02/hw09.17ap02.html