7.3.1 Lion and Mouse

Introduction

The following example has been adapted from the research of Henrik Schärfe.

Modified by Ulrik Petersen for the purposes of this course.

Example

//
// Lion-and-Mouse example.  One of Aesop's fables.
//
// Adapted from the work of Henrik Scharfe 
// by Ulrik Petersen
// Created: September 13, 2003
// Last update: September 23, 2003
//
// Available in the AAU directory as Lion-and-Mouse.plgCG
//
// The text is:
//
// "A LION was awakened from sleep by a Mouse running over his face. 
// Rising up angrily, he caught him and was about to kill him, when the 
// Mouse piteously entreated, saying: "If you would only spare my life, 
// I would be sure to repay your kindness." The Lion laughed and let him go.
// It happened shortly after this that the Lion was caught by some hunters, 
// who bound him by ropes to the ground. The Mouse, recognizing his roar,
// came, gnawed the rope with his teeth, and set him free, exclaimed "You 
// ridiculed the idea of my ever being able to help you, expecting to receive 
// from me any repayment of your favor; now you know that it is possible 
// for even a Mouse to help a Lion." 
//

// Type-hierarchy
entity > physical, abstract.
abstract > description, proposition, schema.
description > manner, idea, attribute.
manner > angrily, piteously.
attribute > possible.
proposition > if, then.
schema > quantity.
physical > process, object, situation, execution.
process > act, life.
object > animal, face, person, artefact, natural_resource, bodypart.
situation > state.
execution > kindness, temporal_reference.

// Catalog of instances.

animal = lion, mouse.
person = hunters, you, me.
act = run, caught, awakened, rising_up, entreated, spare, repay,
          about_to_kill, laughed, let_go, bound, recognizing, roar, gnawed,
          set_free, exclaimed, ridiculed, help, know.
quantity = some.
temporal_reference = shortly_after.
artefact = ropes.
natural_resource = ground.
body_part = teeth.
state = being_able.


// Each fable has a part-number (e.g., pa1, pa2).
// Each part corresponds to roughly one sentence.
//

fab4(pa1,

    [act: awakened]-
    -ptnt->[animal:lion],
    -agnt->[animal:mouse],
    -caus->[situation = [act:run]-
      -agnt->[animal:mouse],
      -path->[face]<-poss-[animal:lion]]).

fab4(pa2,

    [act:caught]-
    -agnt->[animal:lion],
    -ptnt->[animal:mouse],
    -ptim->[act:rising_up]-
      -agnt->[animal:lion],
      -manr->[angrily]).

fab4(pa3,

    [act : entreated = 
       [proposition = 
          [if = [animal:lion]<-agnt-[act:spare]-thme->[life]<-poss-[animal:mouse]
       ]-cond->[then = 
          [act : repay]-
            -agnt->[animal:mouse],
            -thme->[kindness],
            -rcpt->[animal:lion]
                       ]
       ]
    ]-
      -manr->[piteously],
      -agnt->[animal:mouse],
      -rcpt->[animal:lion],
      -ptim->[act:about_to_kill]-
        -agnt->[animal:lion],
        -ptnt->[animal:mouse]).

fab4(pa4,

    [animal:lion]<-agnt-[act:laughed]).

fab4(pa5,

    [act:let_go]-
    -ptnt->[animal:mouse],
    -agnt->[animal:lion]).

fab4(pa6,

    [act:caught]-
    -ptnt->[animal:lion],
    -agnt->[person:hunters]-quan->[quantity:some],
    -ptim->[temporal_reference:shortly_after]).

fab4(pa7,

    [act:bound]-
    -agnt->[person:hunters],
    -ptnt->[animal:lion],
    -inst->[artefact:ropes],
    -dest->[natural_resource:ground]).

fab4(pa8,

    [act:recognizing]-
    -agnt->[animal:mouse],
    -thme->[act:roar]-agnt->[animal:lion]).

fab4(pa9,

    [act:gnawed]-
    -agnt->[animal:mouse],
    -obj->[artefact:ropes],
    -inst->[bodypart:teeth]).

fab4(pa10,

    [act:set_free]-
    -agnt->[animal:mouse],
    -ptnt->[animal:lion]).

fab4(pa11,

    [act : exclaimed = 
       [person:you]<-agnt-[act : ridiculed = 
         [idea = 
              [state: being_able]-
                  -thme->[situation = [act:help]-
                                        -agnt->[person : me],
                                        -rcpt->[person : you]],
                  -expr->[person : me]
              ]
         ]]-
    -agnt->[animal:mouse],
    -rcpt->[animal:lion]).

fab4(pa12,

    [act : exclaimed = [act:know]-
       -agnt->[person:you],
       -thme->[situation = 
                          [animal:mouse]<-agnt-[act:help]-benf->[animal:lion]
                      ]-attr->[possible]
    ]-
    -agnt->[animal:mouse],
    -rcpt->[animal:lion]).



// Rules

// Connect fable number, part, and graph
fable(4, p, g) :- fab4(p, g).

// X does Act Z to Y in graph G where Z and Y are connected by relation R
doesHow(G, X, Y, Z, R) :-
   subsume([entity]<-agnt-[act]-R->[entity], G),
   branchOfCG([act : Z]-agnt->[entity : X], G),
   branchOfCG([act : Z]-R->[entity : Y], G).

// X does Act Z to Y in graph G where Y is a patient of Act Z
doesPtnt(G, X, Y, Z) :-
   doesHow(G, X, Y, Z, ptnt).

// Lion does something (W) to the mouse, where the mouse is a patient of the act
// in fable f, part p
lion_mouse(f, p, W) :-
   fable(f, p, G),
   doesPtnt(G, lion, mouse, W).

// Mouse does something (W) to lion where the lion is a patient of the act
// in fable f, part p
mouse_lion(f, p, W) :-
   fable(f, p, G),
   doesPtnt(G, mouse, lion, W).

// X caught Y
// in fable f, part p
caught(f, p, X, Y) :-
   fable(f, p, G),
   doesPtnt(G, X, Y, caught).

// X exclaimed W to Y
// in fable f, part p
exclaimed(f, p, X, Y, W) :-
   fable(f, p, G),
   doesHow(G, X, Y, exclaimed, rcpt),
   concOfCG([act : exclaimed = W], G).

Usage

The following is an edited transcript of some queries:

?- lion_mouse(f, p, W).
 
{f = 4, p = pa2, W = caught}
{f = 4, p = pa3, W = about_to_kill}
{f = 4, p = pa5, W = let_go}

?- mouse_lion(f, p, W).
 
{f = 4, p = pa1, W = awakened}
{f = 4, p = pa10, W = set_free}

?- caught(f, p, X, Y).
 
{f = 4, p = pa2, X = lion, Y = mouse}
{f = 4, p = pa6, X = hunters, Y = lion}

?- exclaimed(f, p, X, Y, W).
 
{f = 4, p = pa11, X = mouse, Y = lion, W = [act : ridiculed = 
            [idea = [state : being_able] -
                        -thme->[situation = [act : help] -
                                                -agnt->[person : me],
                                                -rcpt->[person : you]],
                        -expr->[person : me]]]-agnt->[person : you]}
{f = 4, p = pa12, X = mouse, Y = lion, W = [act : know] -
            -agnt->[person : you],
            -thme->[situation = [act : help] -
                         -benf->[animal : lion],
                         -agnt->[animal : mouse]]-attr->[possible]}