Prolog 程序范例.doc

3的阶乘：
predicates
factorial(unsigned,real)
clauses
factorial(1,1):-!.
factorial(X,FactX):-
Y=X-1,
factorial(Y,FactY),
FactX=X*FactY.
goal
X=3,
factorial(X,Y).
输出表
domains
list=integer*
predicates
write_a_list(list)
clauses
write_a_list([]).
write_a_list([H|T]):-
write(H),nl,
write_a_list(T).
goal
write_a_list([1,2,3]).
统计表元素个数
domains
list=integer*
predicates
length_of(list,integer)
clauses
length_of([],0).
length_of([_|T],L):-
length_of(T,TailLength),
L=TailLength+1.
goal
length_of([1,2,3],L).
每个元素加1
domains
list=integer*
predicates
add1(list,list)
clauses
add1([],[]).
add1([Head|Tail],[Head1|Tail1]):-Head1=Head+1,
add1(Tail,Tail1).
goal
add1([1,2,3,4],NewList).
删除整数表中的负数
domains
list=integer*
predicates
discard_negatives(list,list)
clauses
discard_negatives([],[]).
discard_negatives([H|T],ProcessedTail):-
H<0,!,
discard_negatives(T,ProcessedTail).
discard_negatives([H|T],[H|ProcessedTail]):-
discard_negatives(T,ProcessedTail).
goaldiscard_negatives([2,-45,3,468],X).
判断表成员
domains
namelist=name*
name=symbol
predicates
member(name,namelist)
clauses
member(Name,[Name|_]).
member(Name,[_|Tail]):-
member(Name,Tail).
goal
member(susan,[ian,susan,john]).
合并表
domains
integerlist=integer*
predicates
append(integerlist,integerlist,integerlist)
clauses
append([],List,List).
append([H|L1],List2,[H|L3]):-
append(L1,List2,L3).
goal
append([1,2,3],[5,6],L).
输出表中元素
domains
integerlist=integer*
namelist=symbol*
predicates
writelist(integerlist)
writelist(namelist)
clauses
writelist([]).
writelist([H|T]):-
write(H,""),
writelist(T).
goalwritelist([1,2,3,4]),nl.
找出一个数字链表的最大数值。
domains/*领域段*/
list=integer*.
predicates/*谓词段*/
max(list,integer)
clauses/*子句段，存放所有的事实和规则*/
max([H],H).
max([H|T],H):-max(T,X),H>=X.
max([H|T],X):-max(T,X),H<X.
动态生成关于N个学生（包括学号、姓名、出生年月日、成绩）的内部事实数据库，并计算学生成绩的平均分。
domains
num=symbol
name=symbol
birthday=date(integer,integer,integer)
score=real
list=score*
facts
stud(num,name,birthday,score)
predicates
run
add_fact(integer)
sumlist(list,real)
clauses