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parent( mary, john).
parent( ann, mary).
female( mary).
mother( x, y) :- parent( x, y), female( x).
grandparent( x, y) :- parent( x, z), parent( z, y).

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parent(Jo, Jill).

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parent( mary, john).
parent( ann, mary).
female( mary).
mother( x, y) :- parent( x, y), female( x).
grandparent( x, y) :- parent( x, z), parent( z, y).

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parent( mary, john).
parent( ann, mary).
female( mary).
mother( x, y) :- parent( x, y), female( x).
grandparent( x, y) :- parent( x, z), parent( z, y).

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parent( mary, john).
parent( ann, mary).
female( mary).
mother( X, Y) :- parent( X, Y), female( X).
grandparent( X, Y) :- parent( X, Z), parent( Z, Y).

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parent( mary, john).
parent( ann, mary).
female( mary).
mother( X, Y) :- parent( X, Y), female( X).
grandparent( X, Y) :- parent( X, Z), parent( Z, Y).

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i( _,[],1 ).
i( [],_,1 ).
i( [A|R],[B|S],W ) :- i( R,S,P ), W is P + A*B.
 
:- i( [1,2,3],[1,2,3],W ), writeln(W).
:- i( [1,2,1,2],[1],W ), writeln(W).
:- i( [1,2,3,4],[],W ), writeln(W).
:- i( [5,3,3],[4,2,2,3],W ), writeln(W).

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i( [],_,0 ).
i( _,[],0 ).
i( [A|R],[A|S],W ) :- i( R,S,P ), W is P + 1.
i( [_|R],[_|S],W ) :- i( R,S,P ), W is P.
 
 
:-i( [1,2,3,4],[1,3,2,4],I ),writeln(I).
:-i( [1,2,3,4],[1,2,3,4],I ),writeln(I).
:-i( [4,3,2,1],[1,2,3,4],I ),writeln(I).
 ...

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i( [],_,0 ).
i( _,[],0 ).
i( [A|R],[A|S],W ) :- i( R,S,P ), W is P + 1.
i( [_|R],[_|S],W ) :- i( R,S,P ), W is P.
 
 
:-i( [1,2,3,4],[1,3,2,4],I ).
:-i( [1,2,3,4],[1,2,3,4],I ).
:-i( [4,3,2,1],[1,2,3,4],I ).
 ...

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i( [],_,0 ).
i( _,[],0 ).
i( [A|R],[A|S],W ) :- i( R,S,P ), W is P + 1.
i( [_|R],[_|S],W ) :- i( R,S,P ), W is P.
 
 
i( [1,2,3,4],[1,3,2,4],I ).
i( [1,2,3,4],[1,2,3,4],I ).
i( [4,3,2,1],[1,2,3,4],I ).
 ...

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scoop(vanilla). scoop(strawberry). scoop(chocolate).
 
cone(Top,Middle,Bottom):-scoop(Top), scoop(Middle), scoop(Bottom).
 
go:- setof(X+Y+Z, cone(X,Y,Z), List), length(List, N), write(N).
go2:- cone(X,Y,Z), write(X+Y+Z), nl, fail.
go3:- setof(X+Y+Z, (cone(X,Y,Z), X\=Y, Y\=Z, X\=Z), List), length(List, N), write(N),nl.

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bsearch(X,Lo,Hi,Y):-Hi=:=Lo+1, X is Lo.
bsearch(X,Lo,Hi,Y):-Hi < Lo+1, fail.
bsearch(X,Lo,Hi,Y):-Hi>= Lo+1, Mid is (Lo+Hi)//2, 
                f(Mid, Val),
                ( Val=<Y, bsearch(X,Mid,Hi,Y)
                ; Val>Y,  bsearch(X,Lo,Mid,Y)
                ).
 
go:-bsearch(X,1,100,49), nl,nl,print(X),nl.

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mother_child(trude, sally).
 
father_child(tom, sally).
father_child(tom, erica).
father_child(mike, tom).
 
sibling(X, Y)      :- parent_child(Z, X), parent_child(Z, Y).
 
parent_child(X, Y) :- father_child(X, Y).
 ...

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mother_child(trude, sally).
 
father_child(tom, sally).
father_child(tom, erica).
father_child(mike, tom).
 
sibling(X, Y)      :- parent_child(Z, X), parent_child(Z, Y).
 
parent_child(X, Y) :- father_child(X, Y).
 ...

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?- write('Hello world!'), nl.
Hello world!
true.
 
?-

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f = 3

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program :- get_char(X),get_char(Y),check(X,Y). 
check('4','2'):-!. 
check(X,Y):-write(X),get_char(Z),check(Y,Z).
:- program.

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program :- get_char(X),get_char(Y),check(X,Y). 
check('4','2'):- write('Finished'),!. 
check(X,Y):-write('|'), write(X), write('|'), write(Y), write('|'), nl, get_char(Z),check(Y,Z).
:- program.

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edge(1,2).
edge(1,3).
edge(2,4).
edge(3,4).
edge(3,5).
edge(3,6).
edge(5,7).
edge(6,7).
isedge(X,Y):-edge(X,Y).
 ...

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man('Haakon VII').
man('Olav V').
man('Harald V').
man('Haakon').
woman('Martha').
woman('Mette-Marit').
woman('Maud').
woman('Sonja').
parent('Haakon VII','Olav V').
 ...

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man('Haakon VII').
man('Olav V').
man('Harald V').
man('Haakon').
woman('Martha').
woman('Mette-Marit').
woman('Maud').
woman('Sonja').
parent('Haakon VII','Olav V').
 ...

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man('Haakon VII').
man('Olav V').
man('Harald V').
man('Haakon').
woman('Martha').
woman('Mette-Marit').
woman('Maud').
woman('Sonja').
parent('Haakon VII','Olav V').
 ...

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man('Haakon VII').
man('Olav V').
man('Harald V').
man('Haakon').
woman('Martha').
woman('Mette-Marit').
woman('Maud').
woman('Sonja').
parent('Haakon VII','Olav V').
 ...

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man(’Haakon VII’).
man(’Olav V’).
man(’Harald V’).
man(’Haakon’).
woman(’Martha’).
woman(’Mette-Marit’).
woman(’Maud’).
woman(’Sonja’).
parent(’Haakon VII’,’Olav V’).
 ...

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witch(X)  <= burns(X) and female(X).
burns(X)  <= wooden(X).
wooden(X) <= floats(X).
floats(X) <= sameweight(duck, X).
 
female(girl).          {by observation}
sameweight(duck,girl). {by experiment }
 
? witch(girl).
 ...

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program :- get_char(X),get_char(Y),check(X,Y). 
check('4','2'):-!. 
check(X,Y):-write(X),get_char(Z),check(Y,Z).
:- program.

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countdown(0) :- write(0), !.
countdown(N) :- write(N), nl, M is N - 1, countdown(M).

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cube :- read(X), calc(X).
calc(stop) :- write(done).
calc(X) :- C is X * X * X, write(C), cube.

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cube :- read(X), calc(X).
calc(stop) :- write(done).
calc(X) :- C is X * X * X, write(C), cube.

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cube :- read(X), calc(X).
calc(stop) :- write(done).
calc(X) :- C is X * X * X, write(C), cube.