def visit_TheoryAtom(self, atom):
"""
Rewrites theory atoms related to parity constraints.
"""
if atom.term.type == _ast.ASTType.Function and len(
atom.term.arguments) == 0:
if atom.term.name in ["odd", "even"]:
self.__remove = True
i = _ast.Symbol(atom.location, _clingo.Number(self.__id))
ct = _ast.Symbol(atom.location,
_clingo.Function(atom.term.name))
head = _ast.SymbolicAtom(
_ast.Function(atom.location, g_aux_name, [i, ct], False))
head = _ast.Literal(atom.location, _ast.Sign.NoSign, head)
self.__add(_ast.Rule(atom.location, head, []))
for element in atom.elements:
head = _ast.Function(
atom.location, "",
[theory_term_to_term(t) for t in element.tuple], False)
head = _ast.SymbolicAtom(
_ast.Function(atom.location, g_aux_name, [i, ct, head],
False))
head = _ast.Literal(atom.location, _ast.Sign.NoSign, head)
body = element.condition
self.__add(_ast.Rule(atom.location, head, body))
self.__id += 1
return atom
def visit_TheoryAtom(self, atom):
"""
Rewrites theory atoms related to temporal formulas.
An atom of form `&tel {...}` is rewritten to `&tel(k) {...}`, atoms of
form `&initial` and `&final` are rewritten to `__initial` and
`__final`, and atoms of form `&true` and `&false` are rewritten to
`#true` and `#false`.
"""
if atom.term.ast_type == _ast.ASTType.Function and len(
atom.term.arguments) == 0:
time = lambda loc: _ast.SymbolicTerm(
loc, _clingo.Function(_tf.g_time_parameter_name))
wrap = lambda loc, atom: _ast.Literal(
loc, _ast.Sign.DoubleNegation, atom) if self.__head else atom
if atom.term.name == "del":
if not self.__negation and not self.__constraint:
raise RuntimeError(
"dynamic formulas not supported in this context: {}".
format(_tf.str_location(atom.location)))
atom.term.arguments = [
_ast.SymbolicTerm(atom.term.location,
_clingo.Function("__t"))
]
elif atom.term.name == "tel":
if self.__head:
atom, rules = self.__head_transformer.transform(atom)
self.__aux_rules.extend(rules)
else:
if not self.__negation and not self.__constraint:
raise RuntimeError(
"temporal formulas not supported in this context: {}"
.format(_tf.str_location(atom.location)))
for element in atom.elements:
if len(element.terms) != 1:
raise RuntimeError(
"invalid temporal formula: {}".format(
_tf.str_location(atom.location)))
self.visit(element.condition)
atom.term = self.__term_transformer.visit(
atom.term, False, True, True, self.__max_shift)
elif atom.term.name == "initial":
atom = wrap(
atom.location,
_ast.SymbolicAtom(
_ast.Function(atom.location, "__initial",
[time(atom.location)], False)))
elif atom.term.name == "final":
atom = wrap(
atom.location,
_ast.SymbolicAtom(
_ast.Function(atom.location, "__final",
[time(atom.location)], False)))
elif atom.term.name == "true":
atom = wrap(atom.location, _ast.BooleanConstant(True))
elif atom.term.name == "false":
atom = wrap(atom.location, _ast.BooleanConstant(False))
return atom
def main(self, prg, files):
"""
Overwrites clingo's main loop taking care of appending the __aux atom.
"""
pos = {"filename": "<generated>", "line": 1, "column": 1}
loc = {"begin": pos, "end": pos}
sym = ast.Symbol(loc, clingo.Function(auxiliary_atom_name, [], True))
aux = ast.Literal(loc, ast.Sign.NoSign, ast.SymbolicAtom(sym))
atf = AuxTransformer(aux)
files = [open(f) for f in files]
if not files:
files.append(sys.stdin)
# prg.add("base", [], "#external " + auxiliary_atom_name + ".")
with prg.builder() as bld:
for f in files:
clingo.parse_program(f.read(),
lambda stm: bld.add(atf.visit(stm)))
atf.add_auxiliary_rules(bld)
prg.ground((("base", ()), ))
prg.solve()
def __aux_atom(self, location, variables, inc=1):
self.__num_aux += inc
return _ast.Literal(
location, _ast.Sign.NoSign,
_ast.SymbolicAtom(
_ast.Function(location, "__aux_{}".format(self.__num_aux - 1),
variables, False)))
def __append_final(self, x, param=None):
loc = x.location
fun = _ast.Function(
loc, "__final",
[_ast.SymbolicTerm(loc, param)] if param is not None else [],
False)
x.body.append(
_ast.Literal(loc, _ast.Sign.NoSign, _ast.SymbolicAtom(fun)))
def add_part(part_name, atom_name, statement, wrap=lambda x: x):
params = [
_ast.Id(loc, _tf.g_time_parameter_name),
_ast.Id(loc, _tf.g_time_parameter_name_alt)
]
callback(_ast.Program(loc, part_name, params))
atom = wrap(
_ast.SymbolicAtom(_ast.Function(loc, atom_name, [time], False)))
callback(statement(loc, atom, []))
def visit(self, x, *args, **kwargs):
ret = super().visit(x, *args, **kwargs)
if self.final and hasattr(ret, "body"):
if x is ret:
ret = copy(x)
loc = ret.location
fun = ast.Function(loc, "finally",
[ast.SymbolicTerm(loc, self.parameter)], False)
atm = ast.SymbolicAtom(fun)
lit = ast.Literal(loc, ast.Sign.NoSign, atm)
ret.body.append(lit)
return ret
def _get_unsat_atoms(self, location: dict, idx):
"""
Creates the 'unsat' and 'not unsat' atoms
"""
unsat_arguments = [idx, self.weight, self.global_variables]
unsat = ast.SymbolicAtom(
ast.Function(location, "unsat", unsat_arguments, False))
not_unsat = ast.Literal(location, ast.Sign.Negation, unsat)
unsat = ast.Literal(location, ast.Sign.NoSign, unsat)
return unsat, not_unsat
def control_add_facts(ctrl, facts):
with ctrl.builder() as bldr:
line = 1
for f in facts:
raw = f.raw if isinstance(f, Predicate) else f
floc = {"filename": "<input>", "line": line, "column": 1}
location = {"begin": floc, "end": floc}
r = ast.Rule(
location,
ast.Literal(location, ast.Sign.NoSign,
ast.SymbolicAtom(ast.Symbol(location, raw))),
[])
bldr.add(r)
line += 1
def __atom(self, location, positive, name, arguments):
"""
Helper function to create an atom.
Arguments:
location -- Location to use.
positive -- Classical sign of the atom.
name -- The name of the atom.
arguments -- The arguments of the atom.
"""
ret = _ast.Function(location, name, arguments + [time_parameter(location)], False)
if not positive:
ret = _ast.UnaryOperation(location, _ast.UnaryOperator.Minus, ret)
return _ast.SymbolicAtom(ret)
def visit_Literal_in_Head_Disjuntion(self, x, *args, **kwargs):
if x.sign == ast.Sign.DoubleNegation:
sign = self.__dnegative_term
elif x.sign == ast.Sign.Negation:
sign = self.__negative_term
else:
sign = self.__positive_term
rule_id = ast.Symbol(x.location, self.__rule_id_number)
sign = ast.Symbol(x.location, sign)
fun = ast.Function(x.location, auxiliary_atom_name,
[rule_id, sign, x.atom.term], False)
new_literal = ast.Literal(x.location, ast.Sign.NoSign,
ast.SymbolicAtom(fun))
self.__auxiliary_atoms.append(new_literal)
rule = ast.Rule(x.location, head=x, body=[new_literal])
self.__auxiliary_rules.append(rule)
return new_literal
def transform(inputs, callback):
"""
Transforms the given list of temporal programs in string form into an ASP
program.
Returns the future predicates whose atoms have to be set to false if
referring to the future, and program parts that have to be regrounded if
there are constraints referring to the future.
Arguments:
inputs -- The list of inputs.
callback -- Callback for rewritten statements.
"""
loc = {
'begin': {
'line': 1,
'column': 1,
'filename': '<transform>'
},
'end': {
'line': 1,
'column': 1,
'filename': '<transform>'
}
}
future_predicates = set()
constraint_parts = {}
time = _ast.Symbol(loc, _clingo.Function(_tf.g_time_parameter_name))
wrap_lit = lambda a: _ast.Literal(loc, _ast.Sign.NoSign, a)
# apply transformer to program
def append(s):
if s is not None:
callback(s)
aux_rules = []
transformer = _prg.ProgramTransformer(future_predicates, constraint_parts,
aux_rules)
for i in inputs:
_clingo.parse_program(i, lambda s: append(transformer.visit(s)))
if aux_rules:
callback(
_ast.Program(loc, "always", [
_ast.Id(loc, _tf.g_time_parameter_name),
_ast.Id(loc, _tf.g_time_parameter_name_alt)
]))
for rule in aux_rules:
callback(rule)
# add auxiliary rules for future predicates
future_sigs = []
if len(future_predicates) > 0:
callback(
_ast.Program(loc, "always", [
_ast.Id(loc, _tf.g_time_parameter_name),
_ast.Id(loc, _tf.g_time_parameter_name_alt)
]))
for name, arity, positive, shift in sorted(future_predicates):
variables = [
_ast.Variable(loc, "{}{}".format(_tf.g_variable_prefix, i))
for i in range(arity)
]
s = _ast.Symbol(loc, _clingo.Number(shift))
t_shifted = _ast.BinaryOperation(loc, _ast.BinaryOperator.Plus,
time, s)
add_sign = lambda lit: lit if positive else _ast.UnaryOperation(
loc, _ast.UnaryOperator.Minus, lit)
p_current = _ast.SymbolicAtom(
add_sign(_ast.Function(loc, name, variables + [time], False)))
f_current = _ast.SymbolicAtom(
add_sign(
_ast.Function(loc, _tf.g_future_prefix + name,
variables + [s, time], False)))
callback(_ast.Rule(loc, wrap_lit(p_current),
[wrap_lit(f_current)]))
future_sigs.append(
(_tf.g_future_prefix + name, arity + 2, positive))
# gather rules for constraints referring to the future
reground_parts = []
if len(constraint_parts) > 0:
for (name, shift), rules in constraint_parts.items():
assert (shift > 0)
params = [
_ast.Id(loc, _tf.g_time_parameter_name),
_ast.Id(loc, _tf.g_time_parameter_name_alt)
]
# parts to be regrounded
part = "{}_0_{}".format(name, shift - 1)
callback(_ast.Program(loc, part, params))
for p, l in rules:
callback(p)
reground_parts.append((name, part, range(shift)))
# parts that no longer have to be regrounded
last_part = "{}_{}".format(name, shift)
callback(_ast.Program(loc, last_part, params))
for p, l in rules:
callback(l)
reground_parts.append((name, last_part, range(shift, shift + 1)))
def add_part(part_name, atom_name, statement, wrap=lambda x: x):
params = [
_ast.Id(loc, _tf.g_time_parameter_name),
_ast.Id(loc, _tf.g_time_parameter_name_alt)
]
callback(_ast.Program(loc, part_name, params))
atom = wrap(
_ast.SymbolicAtom(_ast.Function(loc, atom_name, [time], False)))
callback(statement(loc, atom, []))
add_part('initial', '__initial', _ast.Rule, wrap_lit)
add_part('always', '__final', _tf.External)
reground_parts.append(('always', 'always', range(1)))
reground_parts.append(('dynamic', 'dynamic', range(1)))
reground_parts.append(('initial', 'initial', range(1)))
def no_program(s):
if s.type != _ast.ASTType.Program:
callback(s)
_clingo.parse_program(
_dedent('''\
#theory tel {
formula_body {
& : 7, unary; % prefix for keywords
- : 7, unary; % classical negation
+ : 6, binary, left; % arithmetic +
- : 6, binary, left; % arithmetic -
~ : 5, unary; % negation
< : 5, unary; % previous
< : 5, binary, right; % n x previous
<: : 5, unary; % weak previous
<: : 5, binary, right; % n x weak previous
<? : 5, unary; % eventually-
<* : 5, unary; % always-
<< : 5, unary; % initially
> : 5, unary; % next
> : 5, binary, right; % n x next
>: : 5, unary; % weak next
>: : 5, binary, right; % n x weak next
>? : 5, unary; % eventually+
>* : 5, unary; % always+
>> : 5, unary; % finally
>* : 4, binary, left; % release
>? : 4, binary, left; % until
<* : 4, binary, left; % trigger
<? : 4, binary, left; % since
& : 3, binary, left; % and
| : 2, binary, left; % or
<- : 1, binary, left; % left implication
-> : 1, binary, left; % right implication
<> : 1, binary, left; % equivalence
;> : 0, binary, right; % sequence next
;>: : 0, binary, right; % sequence weak next
<; : 0, binary, left; % sequence previous
<:; : 0, binary, left % sequence weak previous
};
formula_head {
& : 7, unary; % prefix for keywords
- : 7, unary; % classical negation
+ : 6, binary, left; % arithmetic +
- : 6, binary, left; % arithmetic -
~ : 5, unary; % negation
> : 5, unary; % next
> : 5, binary, right; % n x next
>: : 5, unary; % weak next
>: : 5, binary, right; % n x weak next
>? : 5, unary; % eventually+
>* : 5, unary; % always+
>> : 5, unary; % finally
>* : 4, binary, left; % release
>? : 4, binary, left; % until
& : 3, binary, left; % and
| : 2, binary, left; % or
;> : 0, binary, right; % sequence next
;>: : 0, binary, right % sequence weak next
};
&tel/1 : formula_body, body;
&__tel_head/1 : formula_body, head
}.
'''), no_program)
_clingo.parse_program(
_dedent('''\
#theory del {
formula_body {
& : 7, unary; % prefix for keywords
? : 4, unary; % check
* : 3, unary; % kleene star
+ : 2, binary, left; % choice
;; : 1, binary, left; % sequence
.>? : 0, binary, right; % diamond (eventually)
.>* : 0, binary, right % box (always)
};
&del/1 : formula_body, body
}.
'''), no_program)
return future_sigs, reground_parts
def _convert_rule(self, head, body):
"""
Converts the LPMLN rule using either the unsat atoms
or the simplified approach without them (default setting)
"""
loc = head.location
idx, constraint_weight, priority = self._get_constraint_parameters(loc)
# Choice rules without bound can be skipped
if str(head.ast_type) == 'ASTType.Aggregate':
if head.left_guard is None and head.right_guard is None:
return [ast.Rule(loc, head, body)]
else:
not_head = ast.Literal(loc, ast.Sign.Negation, head)
else:
not_head = ast.Literal(loc, ast.Sign.Negation, head.atom)
# Create ASP rules
# TODO: Better way to insert and delete items from body?
if self.use_unsat:
unsat, not_unsat = self._get_unsat_atoms(loc, idx)
# Rule 1 (unsat :- Body, not Head)
body.insert(0, not_head)
asp_rule1 = ast.Rule(loc, unsat, body)
# Rule 2 (Head :- Body, not unsat)
del body[0]
body.insert(0, not_unsat)
asp_rule2 = ast.Rule(loc, head, body)
# Rule 3 (weak constraint unsat)
asp_rule3 = ast.Minimize(loc, constraint_weight, priority,
[idx, self.global_variables], [unsat])
return [asp_rule1, asp_rule2, asp_rule3]
else:
asp_rules = []
# Choice rules with bounds, e.g. 'w : { a; b } = 1 :- B.'
# get converted to two rules:
# w : { a ; b } :- B. --> { a ; b } :- B.
# w : :- not { a ; b } = 1. --> :~ B, not {a ; b} = 1. [w,id, X]
if str(head.ast_type) == 'ASTType.Aggregate':
agg1 = ast.Aggregate(loc, None, head.elements, None)
asp_rules.append(ast.Rule(loc, agg1, body))
body.insert(0, not_head)
# Convert integrity constraint 'w: #false :- B.' to weak constraint
# of form: ':~ B. [w, idx, X]'
elif str(head.atom.ast_type
) == 'ASTType.BooleanConstant' and not head.atom.value:
pass
# Convert normal rule 'w: H :- B.' to choice rule and weak
# constraint of form: '{H} :- B.' and ':~ B, not H. [w, idx, X]'
else:
cond_head = ast.ConditionalLiteral(loc, head, [])
choice_head = ast.Aggregate(loc, None, [cond_head], None)
asp_rules.append(ast.Rule(loc, choice_head, body))
body.insert(0, not_head)
# TODO: Should the two solve calls work with unsat as well?
if self.two_solve_calls and str(priority) == '0':
ext_helper_atom = ast.SymbolicAtom(
ast.Function(loc, 'ext_helper', [], False))
ext_helper_atom = ast.Literal(loc, ast.Sign.NoSign,
ext_helper_atom)
body.insert(0, ext_helper_atom)
weak_constraint = ast.Minimize(loc, constraint_weight, priority,
[idx, self.global_variables], body)
asp_rules.append(weak_constraint)
return asp_rules
def __false_atom(self, location):
return _ast.Literal(
location, _ast.Sign.NoSign,
_ast.SymbolicAtom(
_ast.Function(location, g_tel_false_atom,
[time_parameter(location)], False)))
def visit_SymbolicAtom(self, x):
"""
Unpool atoms of form p(X).
"""
return [ast.SymbolicAtom(y) for y in unpool_term(x.term)]
