Add more Prolog samples

Closes #233

5 files changed, 483 insertions, 0 deletions

diff --git a/samples/Prolog/calc.pl b/samples/Prolog/calc.pl
new file mode 100644
index 0000000..b7492ca
--- /dev/null
+++ b/samples/Prolog/calc.pl
@@ -0,0 +1,68 @@
+action_module(calculator) .
+
+
+%[-,-,d1,-] --push(D)-->          [-,-,D,-]  if mode(init)
+push(D) < -
+  mode(init),
+  deny([displayed(D1),mode(init)]),
+  affirm([displayed(D),mode(cont)]).
+
+%[-,-,D1,-] --push(D)-->          [-,-,10*D1+D,-]  if mode(cont)
+push(D) < -
+  mode(cont),
+  deny(displayed(D1)),
+  New = 10*D1 + D,
+  affirm(displayed(New)).
+
+%[a,op,d,m] --push(clear)-->      [0,nop,0,0]
+push(clear) < -
+  deny([accumulator(A),op(O),displayed(D),memory(M),mode(X)]),
+  affirm([accumulator(0),op(nop),displayed(0),memory(0),mode(init)]).
+
+%[a,op,d,m] --push(mem_rec)-->    [a,op,m,m]
+push(mem_rec) < -
+  memory(M),
+  deny([displayed(D),mode(X)]),
+  affirm([displayed(M),mode(init)]).
+
+%[a,op,d,m] --push(plus)-->       [op(a,d),plus,d,m]
+push(plus) < -
+  displayed(D),
+  deny([accumulator(A),op(O),mode(X)]),
+  eval(O,A,D,V),   ; use normal arithmetic, i.e., V=O(A,D)
+  affirm([accumulator(V),op(plus),mode(init)]).
+
+%[a,op,d,m] --push(minus)-->      [op(a,d,minus,d,m]
+push(minus) lt -
+  displayed(D),
+  deny([accumulator(A),op(O),mode(X)]),
+  eval(O,A,D,V),   ; use normal arithmetic, i.e., V=O(A,D)
+  affirm([accumulator(V),op(minus),mode(init)]).
+
+%[a,op,d,m] --push(times)-->      [op(a,d),times,d,m]
+push(times) < -
+  displayed(D),
+  deny([accumulator(A),op(O),mode(X)]),
+  eval(O,A,D,V),   ; use normal arithmetic, i.e., V=O(A,D)
+  affirm([accumulator(V),op(times),mode(init)]).
+
+%[a,op,d,m] --push(equal)-->      [a,nop,op(a,d),m]
+push(equal) < -
+  accumulator(A),
+  deny([op(O),displayed(D),mode(X)]),
+  eval(O,A,D,V),
+  affirm([op(nop),displayed(V),mode(init)]).
+
+%[a,op,d,m] --push(mem_plus)-->   [a,nop,v,plus(m,v)] where v=op(a,d)
+push(mem_plus) < -
+  accumulator(A),
+  deny([op(O),displayed(D),memory(M),mode(X)]),
+  eval(O,A,D,V),
+  eval(plus,M,V,V1),
+  affirm([op(nop),displayed(V),memory(V1),mode(init)]).
+
+%[a,op,d,m] --push(plus_minus)--> [a,op,-d,m]
+push(clear) < -
+  deny([displayed(D),mode(X)]),
+  eval(minus,0,D,V),
+  affirm([displayed(V),mode(init)]).
diff --git a/samples/Prolog/normal_form.pl b/samples/Prolog/normal_form.pl
new file mode 100644
index 0000000..808e522
--- /dev/null
+++ b/samples/Prolog/normal_form.pl
@@ -0,0 +1,94 @@
+%%----- normalize(+Wff,-NormalClauses) ------
+normalize(Wff,NormalClauses) :-
+   conVert(Wff,[],S),
+   cnF(S,T),
+   flatten_and(T,U),
+   make_clauses(U,NormalClauses).
+
+%%-----  make a sequence out of a conjunction -----
+flatten_and(X /\ Y, F) :-
+   !,
+   flatten_and(X,A),
+   flatten_and(Y, B),
+   sequence_append(A,B,F).
+flatten_and(X,X).
+
+%%-----  make a sequence out of a disjunction -----
+flatten_or(X \/ Y, F) :-
+   !,
+   flatten_or(X,A),
+   flatten_or(Y,B),
+   sequence_append(A,B,F).
+flatten_or(X,X).
+
+
+%%----- append two sequences -------------------------------
+sequence_append((X,R),S,(X,T)) :- !, sequence_append(R,S,T).
+sequence_append((X),S,(X,S)).
+
+%%----- separate into positive and negative literals -----------
+separate((A,B),P,N) :-
+   !,
+   (A = ~X -> N=[X|N1],
+               separate(B,P,N1)
+             ;
+               P=[A|P1],
+               separate(B,P1,N) ).
+separate(A,P,N) :-
+   (A = ~X -> N=[X],
+               P = []
+            ;
+               P=[A],
+               N = [] ).
+
+%%----- tautology ----------------------------
+tautology(P,N) :- some_occurs(N,P).
+
+some_occurs([F|R],B) :-
+   occurs(F,B) | some_occurs(R,B).
+
+occurs(A,[F|_]) :-
+   A == F,
+   !.
+occurs(A,[_|R]) :-
+   occurs(A,R).
+
+make_clauses((A,B),C) :-
+   !,
+   flatten_or(A,F),
+   separate(F,P,N),
+   (tautology(P,N) ->
+      make_clauses(B,C)
+          ;
+      make_clause(P,N,D),
+      C = [D|R],
+      make_clauses(B,R) ).
+make_clauses(A,C) :-
+   flatten_or(A,F),
+   separate(F,P,N),
+   (tautology(P,N) ->
+       C = []
+        ;
+       make_clause(P,N,D),
+       C = [D] ).
+
+make_clause([],N, false :- B) :-
+   !,
+   make_sequence(N,B,',').
+make_clause(P,[],H) :-
+   !,
+   make_sequence(P,H,'|').
+make_clause(P,N, H :- T) :-
+   make_sequence(P,H,'|'),
+   make_sequence(N,T,',').
+
+make_sequence([A],A,_) :- !.
+make_sequence([F|R],(F|S),'|') :-
+   make_sequence(R,S,'|').
+make_sequence([F|R],(F,S),',') :-
+   make_sequence(R,S,',').
+
+write_list([F|R]) :-
+   write(F), write('.'), nl,
+   write_list(R).
+write_list([]).
diff --git a/samples/Prolog/puzzle.pl b/samples/Prolog/puzzle.pl
new file mode 100644
index 0000000..9b0deb9
--- /dev/null
+++ b/samples/Prolog/puzzle.pl
@@ -0,0 +1,287 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%
+%%%     A* Algorithm
+%%%
+%%%
+%%%     Nodes have form    S#D#F#A
+%%%            where S describes the state or configuration
+%%%                  D is the depth of the node
+%%%                  F is the evaluation function value
+%%%                  A is the ancestor list for the node
+
+:- op(400,yfx,'#').    /* Node builder notation */
+
+solve(State,Soln) :- f_function(State,0,F),
+                     search([State#0#F#[]],S), reverse(S,Soln).
+
+f_function(State,D,F) :- h_function(State,H),
+                         F is D + H.
+
+search([State#_#_#Soln|_], Soln) :- goal(State).
+search([B|R],S) :- expand(B,Children),
+                   insert_all(Children,R,Open),
+                   search(Open,S).
+
+insert_all([F|R],Open1,Open3) :- insert(F,Open1,Open2),
+                                 insert_all(R,Open2,Open3).
+insert_all([],Open,Open).
+
+insert(B,Open,Open) :- repeat_node(B,Open), ! .
+insert(B,[C|R],[B,C|R]) :- cheaper(B,C), ! .
+insert(B,[B1|R],[B1|S]) :- insert(B,R,S), !.
+insert(B,[],[B]).
+
+repeat_node(P#_#_#_, [P#_#_#_|_]).
+
+cheaper( _#_#F1#_ , _#_#F2#_ ) :- F1 < F2.
+
+expand(State#D#_#S,All_My_Children) :-
+     bagof(Child#D1#F#[Move|S],
+           (D1 is D+1,
+             move(State,Child,Move),
+             f_function(Child,D1,F)),
+           All_My_Children).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%
+%%%     8-puzzle solver
+%%%
+%%%
+%%%     State have form    A/B/C/D/E/F/G/H/I
+%%%            where {A,...,I} = {0,...,8}
+%%%               0 represents the empty tile
+%%%
+
+goal(1/2/3/8/0/4/7/6/5).
+
+%%% The puzzle moves
+
+left( A/0/C/D/E/F/H/I/J , 0/A/C/D/E/F/H/I/J ).
+left( A/B/C/D/0/F/H/I/J , A/B/C/0/D/F/H/I/J ).
+left( A/B/C/D/E/F/H/0/J , A/B/C/D/E/F/0/H/J ).
+left( A/B/0/D/E/F/H/I/J , A/0/B/D/E/F/H/I/J ).
+left( A/B/C/D/E/0/H/I/J , A/B/C/D/0/E/H/I/J ).
+left( A/B/C/D/E/F/H/I/0 , A/B/C/D/E/F/H/0/I ).
+
+up( A/B/C/0/E/F/H/I/J , 0/B/C/A/E/F/H/I/J ).
+up( A/B/C/D/0/F/H/I/J , A/0/C/D/B/F/H/I/J ).
+up( A/B/C/D/E/0/H/I/J , A/B/0/D/E/C/H/I/J ).
+up( A/B/C/D/E/F/0/I/J , A/B/C/0/E/F/D/I/J ).
+up( A/B/C/D/E/F/H/0/J , A/B/C/D/0/F/H/E/J ).
+up( A/B/C/D/E/F/H/I/0 , A/B/C/D/E/0/H/I/F ).
+
+right( A/0/C/D/E/F/H/I/J , A/C/0/D/E/F/H/I/J ).
+right( A/B/C/D/0/F/H/I/J , A/B/C/D/F/0/H/I/J ).
+right( A/B/C/D/E/F/H/0/J , A/B/C/D/E/F/H/J/0 ).
+right( 0/B/C/D/E/F/H/I/J , B/0/C/D/E/F/H/I/J ).
+right( A/B/C/0/E/F/H/I/J , A/B/C/E/0/F/H/I/J ).
+right( A/B/C/D/E/F/0/I/J , A/B/C/D/E/F/I/0/J ).
+
+down( A/B/C/0/E/F/H/I/J , A/B/C/H/E/F/0/I/J ).
+down( A/B/C/D/0/F/H/I/J , A/B/C/D/I/F/H/0/J ).
+down( A/B/C/D/E/0/H/I/J , A/B/C/D/E/J/H/I/0 ).
+down( 0/B/C/D/E/F/H/I/J , D/B/C/0/E/F/H/I/J ).
+down( A/0/C/D/E/F/H/I/J , A/E/C/D/0/F/H/I/J ).
+down( A/B/0/D/E/F/H/I/J , A/B/F/D/E/0/H/I/J ).
+
+%%% the heuristic function
+h_function(Puzz,H) :- p_fcn(Puzz,P),
+                      s_fcn(Puzz,S),
+                      H is P + 3*S.
+
+
+%%% the move
+move(P,C,left) :-  left(P,C).
+move(P,C,up) :-  up(P,C).
+move(P,C,right) :-  right(P,C).
+move(P,C,down) :-  down(P,C).
+
+%%% the Manhattan distance function
+p_fcn(A/B/C/D/E/F/G/H/I, P) :-
+     a(A,Pa), b(B,Pb), c(C,Pc),
+     d(D,Pd), e(E,Pe), f(F,Pf),
+     g(G,Pg), h(H,Ph), i(I,Pi),
+     P is Pa+Pb+Pc+Pd+Pe+Pf+Pg+Ph+Pg+Pi.
+
+a(0,0). a(1,0). a(2,1). a(3,2). a(4,3). a(5,4). a(6,3). a(7,2). a(8,1).
+b(0,0). b(1,1). b(2,0). b(3,1). b(4,2). b(5,3). b(6,2). b(7,3). b(8,2).
+c(0,0). c(1,2). c(2,1). c(3,0). c(4,1). c(5,2). c(6,3). c(7,4). c(8,3).
+d(0,0). d(1,1). d(2,2). d(3,3). d(4,2). d(5,3). d(6,2). d(7,2). d(8,0).
+e(0,0). e(1,2). e(2,1). e(3,2). e(4,1). e(5,2). e(6,1). e(7,2). e(8,1).
+f(0,0). f(1,3). f(2,2). f(3,1). f(4,0). f(5,1). f(6,2). f(7,3). f(8,2).
+g(0,0). g(1,2). g(2,3). g(3,4). g(4,3). g(5,2). g(6,2). g(7,0). g(8,1).
+h(0,0). h(1,3). h(2,3). h(3,3). h(4,2). h(5,1). h(6,0). h(7,1). h(8,2).
+i(0,0). i(1,4). i(2,3). i(3,2). i(4,1). i(5,0). i(6,1). i(7,2). i(8,3).
+
+%%% the out-of-cycle function
+s_fcn(A/B/C/D/E/F/G/H/I, S) :-
+     s_aux(A,B,S1), s_aux(B,C,S2), s_aux(C,F,S3),
+     s_aux(F,I,S4), s_aux(I,H,S5), s_aux(H,G,S6),
+     s_aux(G,D,S7), s_aux(D,A,S8), s_aux(E,S9),
+     S is S1+S2+S3+S4+S5+S6+S7+S8+S9.
+
+s_aux(0,0) :- !.
+s_aux(_,1).
+
+s_aux(X,Y,0) :- Y is X+1, !.
+s_aux(8,1,0) :- !.
+s_aux(_,_,2).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%
+%%%     8-puzzle animation -- using VT100 character graphics
+%%%
+%%%
+%%%
+
+puzzle(P) :- solve(P,S),
+             animate(P,S),
+             message.
+
+animate(P,S) :- initialize(P),
+                cursor(1,2), write(S),
+                cursor(1,22), write('Hit ENTER to step solver.'),
+                get0(_X),
+                play_back(S).
+
+:- dynamic location/3.
+
+initialize(A/B/C/D/E/F/H/I/J) :-
+  cls,
+  retractall(location(_,_,_)),
+  assert(location(A,20,5)),
+  assert(location(B,30,5)),
+  assert(location(C,40,5)),
+  assert(location(F,40,10)),
+  assert(location(J,40,15)),
+  assert(location(I,30,15)),
+  assert(location(H,20,15)),
+  assert(location(D,20,10)),
+  assert(location(E,30,10)), draw_all.
+
+draw_all :- draw(1), draw(2), draw(3), draw(4),
+            draw(5), draw(6), draw(7), draw(8).
+
+%%% play_back([left,right,up,...]).
+play_back([M|R]) :- call(M), get0(_X), play_back(R).
+play_back([]) :- cursor(1,24).  %%% Put cursor out of the way
+
+message :- nl,nl,
+   write('    ********************************************'), nl,
+   write('    *  Enter 8-puzzle goals in the form ...    *'), nl,
+   write('    *     ?-  puzzle(0/8/1/2/4/3/7/6/5).       *'), nl,
+   write('    *   Enter goal ''message'' to reread this.   *'), nl,
+   write('    ********************************************'), nl, nl.
+
+
+cursor(X,Y) :- put(27), put(91), %%% ESC [
+               write(Y),
+               put(59),           %%%   ;
+               write(X),
+               put(72).           %%%   M
+
+%%% clear the screen, quickly
+cls :-  put(27), put("["), put("2"), put("J").
+
+%%% video attributes -- bold and blink not working
+plain         :- put(27), put("["), put("0"), put("m").
+reverse_video :- put(27), put("["), put("7"), put("m").
+
+
+%%% Tile objects, character map(s)
+%%% Each tile should be drawn using the character map,
+%%%   drawn at 'location', which is asserted and retracted
+%%%   by 'playback'.
+character_map(N, [ [' ',' ',' ',' ',' ',' ',' '],
+                   [' ',' ',' ', N ,' ',' ',' '],
+                   [' ',' ',' ',' ',' ',' ',' '] ]).
+
+
+%%% move empty tile (spot) to the left
+left :- retract(location(0,X0,Y0)),
+        Xnew is X0 - 10,
+        location(Tile,Xnew,Y0),
+        assert(location(0,Xnew,Y0)),
+        right(Tile),right(Tile),right(Tile),
+        right(Tile),right(Tile),
+        right(Tile),right(Tile),right(Tile),
+        right(Tile),right(Tile).
+
+up :- retract(location(0,X0,Y0)),
+      Ynew is Y0 - 5,
+      location(Tile,X0,Ynew),
+      assert(location(0,X0,Ynew)),
+      down(Tile),down(Tile),down(Tile),down(Tile),down(Tile).
+
+right :- retract(location(0,X0,Y0)),
+         Xnew is X0 + 10,
+         location(Tile,Xnew,Y0),
+         assert(location(0,Xnew,Y0)),
+         left(Tile),left(Tile),left(Tile),left(Tile),left(Tile),
+         left(Tile),left(Tile),left(Tile),left(Tile),left(Tile).
+
+down :- retract(location(0,X0,Y0)),
+        Ynew is Y0 + 5,
+        location(Tile,X0,Ynew),
+        assert(location(0,X0,Ynew)),
+        up(Tile),up(Tile),up(Tile),up(Tile),up(Tile).
+
+
+draw(Obj) :- reverse_video, character_map(Obj,M),
+             location(Obj,X,Y),
+             draw(X,Y,M), plain.
+
+%%% hide tile
+hide(Obj) :- character_map(Obj,M),
+             location(Obj,X,Y),
+             hide(X,Y,M).
+
+hide(_,_,[]).
+hide(X,Y,[R|G]) :- hide_row(X,Y,R),
+                   Y1 is Y + 1,
+                   hide(X,Y1,G).
+
+hide_row(_,_,[]).
+hide_row(X,Y,[_|R]) :- cursor(X,Y),
+                       write(' '),
+                       X1 is X + 1,
+                       hide_row(X1,Y,R).
+
+%%% draw tile
+draw(_,_,[]).
+draw(X,Y,[R|G]) :- draw_row(X,Y,R),
+                   Y1 is Y + 1,
+                   draw(X,Y1,G).
+
+draw_row(_,_,[]).
+draw_row(X,Y,[P|R]) :- cursor(X,Y),
+                       write(P),
+                       X1 is X + 1,
+                       draw_row(X1,Y,R).
+
+%%% Move an Object up
+up(Obj)    :- hide(Obj),
+              retract(location(Obj,X,Y)),
+              Y1 is Y - 1,
+              assert(location(Obj,X,Y1)),
+              draw(Obj).
+
+down(Obj)  :- hide(Obj),
+              retract(location(Obj,X,Y)),
+              Y1 is Y + 1,
+              assert(location(Obj,X,Y1)),
+              draw(Obj).
+
+left(Obj)  :- hide(Obj),
+              retract(location(Obj,X,Y)),
+              X1 is X - 1,
+              assert(location(Obj,X1,Y)),
+              draw(Obj).
+
+right(Obj) :- hide(Obj),
+              retract(location(Obj,X,Y)),
+              X1 is X + 1,
+              assert(location(Obj,X1,Y)),
+              draw(Obj).
+
+:- message.
diff --git a/samples/Prolog/quicksort.pl b/samples/Prolog/quicksort.pl
new file mode 100644
index 0000000..eb4467b
--- /dev/null
+++ b/samples/Prolog/quicksort.pl
@@ -0,0 +1,13 @@
+partition([], _, [], []).
+partition([X|Xs], Pivot, Smalls, Bigs) :-
+    (   X @< Pivot ->
+        Smalls = [X|Rest],
+        partition(Xs, Pivot, Rest, Bigs)
+    ;   Bigs = [X|Rest],
+        partition(Xs, Pivot, Smalls, Rest)
+    ).
+
+quicksort([])     --> [].
+quicksort([X|Xs]) -->
+    { partition(Xs, X, Smaller, Bigger) },
+    quicksort(Smaller), [X], quicksort(Bigger).
diff --git a/samples/Prolog/turing.pl b/samples/Prolog/turing.pl
new file mode 100644
index 0000000..82fe104
--- /dev/null
+++ b/samples/Prolog/turing.pl
@@ -0,0 +1,21 @@
+turing(Tape0, Tape) :-
+    perform(q0, [], Ls, Tape0, Rs),
+    reverse(Ls, Ls1),
+    append(Ls1, Rs, Tape).
+
+perform(qf, Ls, Ls, Rs, Rs) :- !.
+perform(Q0, Ls0, Ls, Rs0, Rs) :-
+    symbol(Rs0, Sym, RsRest),
+    once(rule(Q0, Sym, Q1, NewSym, Action)),
+    action(Action, Ls0, Ls1, [NewSym|RsRest], Rs1),
+    perform(Q1, Ls1, Ls, Rs1, Rs).
+
+symbol([], b, []).
+symbol([Sym|Rs], Sym, Rs).
+
+action(left, Ls0, Ls, Rs0, Rs) :- left(Ls0, Ls, Rs0, Rs).
+action(stay, Ls, Ls, Rs, Rs).
+action(right, Ls0, [Sym|Ls0], [Sym|Rs], Rs).
+
+left([], [], Rs0, [b|Rs0]).
+left([L|Ls], Ls, Rs, [L|Rs]).