30 lines
649 B
Plaintext
30 lines
649 B
Plaintext
#include <incmode>.
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#program base.
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% Establish initial state
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holds(Var, Val, 0) :- initialState(Var, Val).
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#program step(t).
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% Perform actions
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1 {occurs(action(A), t) : action(A)} 1.
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% Check preconditions
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:- occurs(A, t), precondition(A, Var, Val), not holds(Var, Val, t - 1).
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% Apply effects
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caused(Var, Val, t) :- occurs(A, t), postcondition(A, Var, Val).
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modified(Var, t) :- caused(Var, Val, t).
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holds(Var, Val, t) :- caused(Var, Val, t).
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holds(Var, Val, t) :- holds(Var, Val, t - 1), not modified(Var, t).
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#program check(t).
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% Verify that goal is met
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:- query(t), goal(Var, Val), not holds(Var, Val, t).
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#show query/1.
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#show occurs/2.
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