From 92f3018b89793323a7915bbc1f9a5f3def1d3729 Mon Sep 17 00:00:00 2001 From: Torsten Schaub Date: Mon, 22 Aug 2016 22:35:35 +0200 Subject: [PATCH 1/3] first throw at PDDL specifc encoding for sequential planning using Boolean fluents only --- .../pddl-sequential-incremental-boolean.lp | 31 +++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 encodings/pddl-sequential-incremental-boolean.lp diff --git a/encodings/pddl-sequential-incremental-boolean.lp b/encodings/pddl-sequential-incremental-boolean.lp new file mode 100644 index 0000000..da03935 --- /dev/null +++ b/encodings/pddl-sequential-incremental-boolean.lp @@ -0,0 +1,31 @@ +#include . + +#program base. + + precondition(Action,variable(Fluent),Value) :- precondition(Action, variable(Fluent),value(Fluent,Value)). +postcondition(Action,variable(Fluent),Value) :- postcondition(Action,effect(unconditional),variable(Fluent),value(Fluent,Value)). + +holds(variable(Fluent),0) :- initialState(variable(Fluent),value(Fluent,true)). + +#program step(t). + + { occurs(Action,t) : action(Action) } = 1. + +:- occurs(Action,t), precondition(Action,Fluent,true), not holds(Fluent,t-1). +:- occurs(Action,t), precondition(Action,Fluent,false), holds(Fluent,t-1). + +caused(Fluent,t) :- occurs(Action,t), postcondition(Action,Fluent,true). + +holds(Fluent,t) :- caused(Fluent,t). +holds(Fluent,t) :- holds(Fluent,t-1), not occurs(Action,t) : postcondition(Action,Fluent,false). + +#program check(t). + +goalAt(t) :- holds(variable(Variable),t) : goal(variable(Variable), value(Variable,true)); + not holds(variable(Variable),t) : goal(variable(Variable), value(Variable,false)). + + :- not goalAt(t), query(t). + +#show occurs/2. +% #show holds/2. + From d7b8cec50dee8cf331cafa293eac25d78a1fb7ce Mon Sep 17 00:00:00 2001 From: Torsten Schaub Date: Tue, 23 Aug 2016 11:51:03 +0200 Subject: [PATCH 2/3] simple fixed horizon-based encoding for sequential PDDL planning --- encodings/pddl-sequential-horizon-boolean.lp | 28 ++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 encodings/pddl-sequential-horizon-boolean.lp diff --git a/encodings/pddl-sequential-horizon-boolean.lp b/encodings/pddl-sequential-horizon-boolean.lp new file mode 100644 index 0000000..03c2605 --- /dev/null +++ b/encodings/pddl-sequential-horizon-boolean.lp @@ -0,0 +1,28 @@ +#const horizon=1. + +step(0..horizon). + + precondition(Action,variable(Fluent),Value) :- precondition(Action, variable(Fluent),value(Fluent,Value)). +postcondition(Action,variable(Fluent),Value) :- postcondition(Action,effect(unconditional),variable(Fluent),value(Fluent,Value)). + +holds(variable(Fluent),0) :- initialState(variable(Fluent),value(Fluent,true)). + + { occurs(Action,T) : action(Action) } = 1 :- step(T), T>0. + +:- occurs(Action,T), precondition(Action,Fluent,true), not holds(Fluent,T-1). +:- occurs(Action,T), precondition(Action,Fluent,false), holds(Fluent,T-1). + +caused(Fluent,T) :- occurs(Action,T), postcondition(Action,Fluent,true). + +holds(Fluent,T) :- caused(Fluent,T). +holds(Fluent,T) :- holds(Fluent,T-1), not occurs(Action,T) : postcondition(Action,Fluent,false); T<=horizon. + +goalAt(T) :- holds(variable(Variable),T) : goal(variable(Variable), value(Variable,true)); + not holds(variable(Variable),T) : goal(variable(Variable), value(Variable,false)); + T=horizon. + + :- not goalAt(horizon). + +#show occurs/2. +% #show holds/2. + From 7dfe760285fc5a6d5dde3e6c25b66e193eafab98 Mon Sep 17 00:00:00 2001 From: Torsten Schaub Date: Tue, 23 Aug 2016 18:31:33 +0200 Subject: [PATCH 3/3] PRELIMINARY version of an encoding for sequential SAS planning featuring: axioms and conditional effects (extending Patrick's basic multi-valued encoding) --- ...remental-multivalued-axioms-condeffects.lp | 52 +++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 encodings/sas-sequential-incremental-multivalued-axioms-condeffects.lp diff --git a/encodings/sas-sequential-incremental-multivalued-axioms-condeffects.lp b/encodings/sas-sequential-incremental-multivalued-axioms-condeffects.lp new file mode 100644 index 0000000..5dad258 --- /dev/null +++ b/encodings/sas-sequential-incremental-multivalued-axioms-condeffects.lp @@ -0,0 +1,52 @@ +#include . + +% Check feature requirements +% :- requires(feature(actionCosts)). + +#program base. + +% Establish initial state +holds(Variable, Value, 0) :- initialState(Variable, Value), not stateVariable(Variable). + +% Identify (head and) state variables +headVariable(Rule,Variable) :- variable(Variable), axiomRule(Rule), postcondition(Rule,_,Variable,_). +stateVariable(Variable) :- headVariable(_,Variable). + +#program step(t). % t=1,2,... + +% Perform actions +1 {occurs(Action, t) : action(Action)} 1. + +% Check preconditions +:- occurs(Action, t), precondition(Action, Variable, Value), not holds(Variable, Value, t - 1). + +% Apply effects +caused(Variable, Value, t) :- occurs(Action, t), postcondition(Action, Effect, Variable, Value), + holds(Variable', Value', t) : precondition(Effect, Variable', Value'). +modified(Variable, t) :- caused(Variable, Value, t). + +holds(Variable, Value, t) :- caused(Variable, Value, t). +holds(Variable, Value, t) :- holds(Variable, Value, t - 1), not modified(Variable, t). + +#program check(t). % t=0,1,... + +% Check that variables have unique values +:- variable(Variable), {holds(Variable, Value, t) : contains(Variable, Value)} != 1. + +% Check mutexes +:- mutexGroup(MutexGroup), {holds(Variable, Value, t) : contains(MutexGroup, Variable, Value)} > 1. + +% Apply axioms +derived(Variable, Value, t) :- axiomRule(Rule), postcondition(Rule,_,Variable,Value), + holds(Variable', Value', t) : precondition(Rule, Variable', Value'), not headVariable(Rule,Variable'). + +modified(Variable, t) :- derived(Variable, Value, t). + +holds(Variable, Value, t) :- derived(Variable, Value, t), stateVariable(Variable). +holds(Variable, Value, t) :- not modified(Variable, t), stateVariable(Variable), initialState(Variable, Value). + +% Verify that goal is met +:- query(t), goal(Variable, Value), not holds(Variable, Value, t). + +#show occurs/2. +% #show holds/3.