Prisoners Dilemma: Move rules to subdirectory

12 files changed, 64 insertions, 0 deletions

diff --git a/rules/always_coorporate.pl b/rules/always_coorporate.pl
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+++ b/rules/always_coorporate.pl
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+always_coorporate(_, c, _, _).
diff --git a/rules/always_defect.pl b/rules/always_defect.pl
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+++ b/rules/always_defect.pl
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+always_defect(_, d, _, _).
diff --git a/rules/grudger.pl b/rules/grudger.pl
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+++ b/rules/grudger.pl
@@ -0,0 +1,8 @@
+% Grudger, Spiteful:
+% Cooperates until the second has defected, after
+% that move defects forever (he does not forgive).
+% http://euler.fd.cvut.cz/predmety/game_theory/lecture_repeat.pdf
+
+grudger([], c, _, _).
+grudger([d|_], d, _, _).
+grudger([c|Tail], Decision, _, _) :- grudger(Tail, Decision, _, _).
diff --git a/rules/hard_tit4tat.pl b/rules/hard_tit4tat.pl
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index 0000000..8efc124
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+++ b/rules/hard_tit4tat.pl
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+% Hard Tit for Tat:
+% Cooperates unless the opponent has defected
+% at least once in the last two rounds.
+
+hard_tit4tat([A,B|_],d,_,_):-(A=d;B=d),!.
+hard_tit4tat(_,c,_,_).
diff --git a/rules/mistrust_tit4tat.pl b/rules/mistrust_tit4tat.pl
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+++ b/rules/mistrust_tit4tat.pl
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+% Mistrust Tit for Tat:
+% In the first round it defects, than it plays opponent’s move.
+
+% Use opponents last decision
+mistrust_tit4tat([Last|_],Last,_,_).
+% Fallback to defect if history is empty.
+mistrust_tit4tat([],d,_,_).
diff --git a/rules/naive_prober.pl b/rules/naive_prober.pl
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index 0000000..df2bcf5
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+++ b/rules/naive_prober.pl
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+% Naive Prober:
+% Like Tit for Tat, but sometimes, after the opponent has cooperated, it
+% defects (e.g. at random, in one of ten rounds in average).
+
+naive_prober([d|_],d,_,_).
+% but only for for 90% if coorporated
+naive_prober([c|_],Choice,_,_):-random(Number), (Number < 0.1 -> Choice=d; Choice=c).
+% Fallback to coorporate if history is empty.
+naive_prober([],c,_,_).
diff --git a/rules/pavlov.pl b/rules/pavlov.pl
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+++ b/rules/pavlov.pl
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+% Pavlov:
+% Cooperates if and only if both players opted for the
+% same choice in the previous move, otherwise it defects.
+pavlov([], c, _, c):-!.
+pavlov([Choice|_], c, Choice, c):-!.
+pavlov(_, d, _, d).
diff --git a/rules/periodically_ddc.pl b/rules/periodically_ddc.pl
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index 0000000..897986d
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+++ b/rules/periodically_ddc.pl
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+% Plays periodically: Defect–Defect–Coop.
+periodically_ddc(_, d, [],  [1]).
+periodically_ddc(_, d, [1], [2]).
+periodically_ddc(_, c, [2], []).
diff --git a/rules/periodically_ssz.pl b/rules/periodically_ssz.pl
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index 0000000..21cb017
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+++ b/rules/periodically_ssz.pl
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+% Plays periodically: Coop-Coop-Defect
+periodically_ssz(_, c, [],  [1]).
+periodically_ssz(_, c, [1], [2]).
+periodically_ssz(_, d, [2], []).
diff --git a/rules/random_choice.pl b/rules/random_choice.pl
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index 0000000..3bd4a91
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+++ b/rules/random_choice.pl
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+random_choice(_, Choice, _, _) :-
+	random(Number),	(Number < 0.5 -> Choice=c ; Choice=d).
diff --git a/rules/tit42tat.pl b/rules/tit42tat.pl
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+++ b/rules/tit42tat.pl
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+% Select distraction only if opponents both last decision were to distract.
+% See: http://en.wikipedia.org/wiki/Tit_for_tat#Tit_for_two_tats
+
+tit42tat([d,d|_],d,_,_):-!.
+tit42tat(_,c,_,_).
diff --git a/rules/tit4tat.pl b/rules/tit4tat.pl
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index 0000000..2cf520c
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+++ b/rules/tit4tat.pl
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+% Tit for Tat:
+% Begins with cooperation and then plays what its opponent played in the last
+% move (if the opponent defects in some round, Tit for Tat will defect in the
+% following one; to cooperation it responds with cooperation).
+
+% Syntax: MODULE(UserDecisionHistry [in], ModuleDecision [out])
+
+% Use opponents last decision
+tit4tat([Last|_],Last,_,_).
+% Fallback to coorporate if history is empty.
+tit4tat([],c,_,_).