1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
:- object(expert,
imports(protected::descriptors)).
:- info([
author is 'Paulo Moura',
version is 1.1,
date is 2005/3/6,
comment is 'Expert system for bird identification.',
source is 'Example adopted from an Amzi! Inc Prolog book.']).
:- public(identify/0).
:- mode(identify, one).
:- info(identify/0,
[comment is 'Starts a bird identification session.']).
:- private(known_/3).
:- dynamic(known_/3).
:- mode(known_(?nonvar, ?nonvar, ?nonvar), zero_or_more).
:- info(known_/3, [
comment is 'Table of already known facts.',
argnames is ['Answer', 'Attribute', 'Value']]).
identify :-
::retractall(known_(_, _, _)),
write('Bird identification expert system'), nl, nl,
forall(
(order::leaf(Bird), check(Bird)),
(nl, write('Possible identification: '), write(Bird), nl)),
nl, write('No (more) candidates found.').
check(Bird) :-
forall(
(::descriptor(Functor/Arity),
functor(Predicate, Functor, Arity),
Bird::Predicate),
call(Predicate)).
bill(X):-
ask(bill, X).
cheek(X):-
ask(cheek, X).
color(X):-
ask(color, X).
eats(X):-
ask(eats, X).
feed(X):-
ask(feed,X).
feet(X):-
ask(feet, X).
flight(X):-
menuask(flight, X, [ponderous, powerful, agile, flap_glide, other]).
flight_profile(X):-
menuask(flight_profile, X, [flat, v_shaped, other]).
head(X):-
ask(head,X).
live(X) :-
ask(live, X).
neck(X):-
ask(neck, X).
nostrils(X):-
ask(nostrils, X).
size(X):-
menuask(size, X, [large, plump, medium, small]).
tail(X):-
menuask(tail, X, [narrow_at_tip, forked, long_rusty, square, other]).
throat(X):-
ask(throat, X).
voice(X):-
ask(voice,X).
wings(X):-
ask(wings, X).
ask(Attribute,Value):-
::known_(yes, Attribute, Value),
!.
ask(Attribute,Value):-
::known_(_, Attribute, Value),
!, fail.
ask(Attribute,_):-
::known_(yes, Attribute, _),
!, fail.
ask(Attribute, Value):-
write(Attribute), write(': '), write(Value),
write('? (yes or no): '),
read(Answer),
::asserta(known_(Answer, Attribute, Value)),
Answer = yes.
menuask(Attribute,Value, _):-
::known_(yes, Attribute, Value),
!.
menuask(Attribute, _, _):-
::known_(yes, Attribute, _),
!, fail.
menuask(Attribute, AskValue, Menu):-
nl, write('What is the value for '), write(Attribute), write('?'), nl,
display_menu(Menu),
write('Enter the number of choice> '),
read(Num),nl,
pick_menu(Num, AnswerValue, Menu),
::asserta(known_(yes,Attribute,AnswerValue)),
AskValue = AnswerValue.
display_menu(Menu):-
display_menu(Menu, 1).
display_menu([], _).
display_menu([Item| Rest], N):-
write(N), write(' : '), write(Item), nl,
NN is N + 1,
display_menu(Rest, NN).
pick_menu(N, Val, Menu):-
integer(N),
pic_menu(1, N, Val, Menu), !.
pick_menu(Val, Val, _).
pic_menu(_, _, none_of_the_above, []).
pic_menu(N, N, Item, [Item| _]).
pic_menu(Ctr, N, Val, [_| Rest]):-
NextCtr is Ctr + 1,
pic_menu(NextCtr, N, Val, Rest).
:- end_object.
|
