/** Constructor for a node containing an atomic proposition (index into APSet) */
public LTLNode(int ap)
{
_type = type_t.T_AP;
_left = null;
_right = null;
_ap = ap;
}
public static LTLFormula parse(ltl2ba.Node LTLHeadNode, APSet predefined_apset)
{
// boost::char_separator<char> sep(" ");
//ltl_seperator sep; tokenizer tokens(formula, sep);
APSet apset = new APSet();
//tokenizer::iterator it = tokens.begin();
//LTLNode ltl = parse(apset, predefined_apset);
//if (it != tokens.end())
//{
// THROW_EXCEPTION(Exception, "Unexpected character(s) at end of LTL formula: '" + *it + "'");
//}
LTLNode ltl = TranslateLTL(LTLHeadNode, apset, predefined_apset);
APSet apset_ = predefined_apset ?? apset;
return(new LTLFormula(ltl, apset_));
}
/**
* Constructor
* @param root the root node
* @param apset the underlying APSet
*/
public LTLFormula(LTLNode root, APSet apset)
{
_root = root;
_apset = apset;
}
public LTLNode(type_t type, LTLNode left) : this(type, left, null)
{
}
/**
* Generate formula in DNF. Formula has to have only
* AND, OR, TRUE, FALSE, ! as operators, and has to
* be in PNF
*/
public LTLNode toDNF()
{
switch (_type)
{
case type_t.T_TRUE:
return(new LTLNode(type_t.T_TRUE, null));
case type_t.T_FALSE:
return(new LTLNode(type_t.T_FALSE, null));
case type_t.T_NOT:
return(new LTLNode(type_t.T_NOT, getLeft().toDNF()));
case type_t.T_AP:
return(new LTLNode(getAP()));
case type_t.T_OR:
return(new LTLNode(type_t.T_OR,
getLeft().toDNF(),
getRight().toDNF()));
case type_t.T_AND:
{
LTLNode left = getLeft().toDNF();
LTLNode right = getRight().toDNF();
if (left.getType() == type_t.T_OR)
{
LTLNode a = left.getLeft();
LTLNode b = left.getRight();
if (right.getType() == type_t.T_OR)
{
LTLNode c = right.getLeft();
LTLNode d = right.getRight();
LTLNode a_c = new LTLNode(type_t.T_AND, a, c),
b_c = new LTLNode(type_t.T_AND, b, c),
a_d = new LTLNode(type_t.T_AND, a, d),
b_d = new LTLNode(type_t.T_AND, b, d);
return(new LTLNode(type_t.T_OR,
new LTLNode(type_t.T_OR, a_c, b_c).toDNF(),
new LTLNode(type_t.T_OR, a_d, b_d).toDNF()));
}
else
{
LTLNode
a_c = new LTLNode(type_t.T_AND, a, right),
b_c = new LTLNode(type_t.T_AND, b, right);
return(new LTLNode(type_t.T_OR, a_c.toDNF(), b_c.toDNF()));
}
}
else if (right.getType() == type_t.T_OR)
{
LTLNode a, b;
a = right.getLeft();
b = right.getRight();
LTLNode
a_c = new LTLNode(type_t.T_AND, left, a),
b_c = new LTLNode(type_t.T_AND, left, b);
return(new LTLNode(type_t.T_OR, a_c.toDNF(), b_c.toDNF()));
}
else
{
return(new LTLNode(type_t.T_AND, left, right));
}
}
default:
throw new Exception("Illegal operator for DNF!");
}
}
/**
* Get a LTLFormula_ptr for the subformula rooted at subroot
*/
public LTLFormula getSubFormula(LTLNode subroot)
{
LTLFormula sub = new LTLFormula(subroot, _apset);
return sub;
}
public LTLNode toPNF(bool negate)
{
switch (_type)
{
case type_t.T_XOR:
throw new Exception("XOR not yet supported!");
case type_t.T_IMPLICATE:
{
if (negate)
{
// ! (a->b) = !(!a | b) = (a & ! b)
return new LTLNode(type_t.T_AND, getLeft().toPNF(), getRight().toPNF(true));
}
else
{
// (a->b) = (!a | b)
return new LTLNode(type_t.T_OR, getLeft().toPNF(true), getRight().toPNF());
}
break;
}
case type_t.T_EQUIV:
{
if (negate)
{
// ! (a<->b) == (a & !b) || (!a & b)
return new
LTLNode(type_t.T_OR,
new LTLNode(type_t.T_AND, getLeft().toPNF(), getRight().toPNF(true)),
new LTLNode(type_t.T_AND, getLeft().toPNF(true), getRight().toPNF()));
}
else
{
// (a<->b) = (!a && !b) || (a && b)
return new LTLNode(type_t.T_OR,
new LTLNode(type_t.T_AND, getLeft().toPNF(true), getRight().toPNF(true)),
new LTLNode(type_t.T_AND, getLeft().toPNF(), getRight().toPNF()));
}
}
case type_t.T_NOT:
if (negate)
{
// double negation
return getLeft().toPNF();////////////////////?? shouldn't be getRight().toPNF()? !(!a) = a
}
else
{
if (getLeft().getType() == type_t.T_AP)
{
// we are in front of an AP, negation is ok
return new LTLNode(type_t.T_NOT, getLeft());
}
else
{
return getLeft().toPNF(true);
}
}
case type_t.T_AP:
if (negate)
{
return new LTLNode(type_t.T_NOT, new LTLNode(_ap));
}
else
{
return new LTLNode(_ap);
}
case type_t.T_TRUE:
if (negate)
{
return new LTLNode(type_t.T_FALSE, null);
}
else
{
return new LTLNode(type_t.T_TRUE, null);
}
case type_t.T_FALSE:
if (negate)
{
return new LTLNode(type_t.T_TRUE, null);
}
else
{
return new LTLNode(type_t.T_FALSE, null);
}
case type_t.T_AND:
// ! (a & b) = (!a | !b)
if (negate)
{
return new LTLNode(type_t.T_OR, getLeft().toPNF(true), getRight().toPNF(true));
}
else
{
return new LTLNode(type_t.T_AND, getLeft().toPNF(), getRight().toPNF());
}
case type_t.T_OR:
if (negate)
{
// ! (a | b) = (!a & !b)
return new LTLNode(type_t.T_AND, getLeft().toPNF(true), getRight().toPNF(true));
}
else
{
return new LTLNode(type_t.T_OR, getLeft().toPNF(), getRight().toPNF());
}
case type_t.T_NEXTSTEP:
// ! (X a) = X (!a)
if (negate)
{
return new LTLNode(type_t.T_NEXTSTEP, getLeft().toPNF(true));
}
else
{
return new LTLNode(type_t.T_NEXTSTEP, getLeft().toPNF());
}
case type_t.T_FINALLY:
// ! (F a) = G (!a) = f V !a
if (negate)
{
return new LTLNode(type_t.T_RELEASE, new LTLNode(type_t.T_FALSE, null), getLeft().toPNF(true));
}
else
{ // F a = t U a
return new LTLNode(type_t.T_UNTIL, new LTLNode(type_t.T_TRUE, null), getLeft().toPNF());
}
case type_t.T_GLOBALLY:
// ! (G a) = F (!a) = t U ! a
if (negate)
{
return new LTLNode(type_t.T_UNTIL, new LTLNode(type_t.T_TRUE, null), getLeft().toPNF(true));
}
else
{ // f V a
return new LTLNode(type_t.T_RELEASE, new LTLNode(type_t.T_FALSE, null), getLeft().toPNF());
}
case type_t.T_UNTIL:
// ! (a U b) = (!a V !b)
if (negate)
{
return new LTLNode(type_t.T_RELEASE, getLeft().toPNF(true), getRight().toPNF(true));
}
else
{
return new LTLNode(type_t.T_UNTIL, getLeft().toPNF(), getRight().toPNF());
}
case type_t.T_RELEASE:
// ! (a R b) = (!a U !b)
if (negate)
{
return new LTLNode(type_t.T_UNTIL, getLeft().toPNF(true), getRight().toPNF(true));
}
else
{
return new LTLNode(type_t.T_RELEASE,
getLeft().toPNF(),
getRight().toPNF());
}
case type_t.T_WEAKUNTIL:
{
LTLNode weak_until = new LTLNode(type_t.T_UNTIL, getLeft(),
new LTLNode(type_t.T_OR, getRight(),
new LTLNode(type_t.T_GLOBALLY, getLeft(), null)));
return weak_until.toPNF(negate);
}
case type_t.T_WEAKRELEASE:
throw new Exception("Operator WEAKRELEASE not yet supported");
case type_t.T_BEFORE:
throw new Exception("Operator BEFORE not yet supported");
}
throw new Exception("Implementation error");
}
/**
* Get a LTLFormula_ptr for the subformula rooted at subroot
*/
public LTLFormula getSubFormula(LTLNode subroot)
{
LTLFormula sub = new LTLFormula(subroot, _apset);
return(sub);
}
/** Constructor for an operator of type */
public LTLNode(type_t type, LTLNode left, LTLNode right)
{
_type = type;
_left = left;
_right = right;
}
/**
* Generate formula in DNF. Formula has to have only
* AND, OR, TRUE, FALSE, ! as operators, and has to
* be in PNF
*/
public LTLNode toDNF()
{
switch (_type)
{
case type_t.T_TRUE:
return new LTLNode(type_t.T_TRUE, null);
case type_t.T_FALSE:
return new LTLNode(type_t.T_FALSE, null);
case type_t.T_NOT:
return new LTLNode(type_t.T_NOT, getLeft().toDNF());
case type_t.T_AP:
return new LTLNode(getAP());
case type_t.T_OR:
return new LTLNode(type_t.T_OR,
getLeft().toDNF(),
getRight().toDNF());
case type_t.T_AND:
{
LTLNode left = getLeft().toDNF();
LTLNode right = getRight().toDNF();
if (left.getType() == type_t.T_OR)
{
LTLNode a = left.getLeft();
LTLNode b = left.getRight();
if (right.getType() == type_t.T_OR)
{
LTLNode c = right.getLeft();
LTLNode d = right.getRight();
LTLNode a_c = new LTLNode(type_t.T_AND, a, c),
b_c = new LTLNode(type_t.T_AND, b, c),
a_d = new LTLNode(type_t.T_AND, a, d),
b_d = new LTLNode(type_t.T_AND, b, d);
return new LTLNode(type_t.T_OR,
new LTLNode(type_t.T_OR, a_c, b_c).toDNF(),
new LTLNode(type_t.T_OR, a_d, b_d).toDNF());
}
else
{
LTLNode
a_c = new LTLNode(type_t.T_AND, a, right),
b_c = new LTLNode(type_t.T_AND, b, right);
return new LTLNode(type_t.T_OR, a_c.toDNF(), b_c.toDNF());
}
}
else if (right.getType() == type_t.T_OR)
{
LTLNode a, b;
a = right.getLeft();
b = right.getRight();
LTLNode
a_c = new LTLNode(type_t.T_AND, left, a),
b_c = new LTLNode(type_t.T_AND, left, b);
return new LTLNode(type_t.T_OR, a_c.toDNF(), b_c.toDNF());
}
else
{
return new LTLNode(type_t.T_AND, left, right);
}
}
default:
throw new Exception("Illegal operator for DNF!");
}
}
public LTLNode(type_t type, LTLNode left)
: this(type, left, null)
{
}
/** Constructor for a node containing an atomic proposition (index into APSet) */
public LTLNode(int ap)
{
_type = type_t.T_AP;
_left = null;
_right = null;
_ap = ap;
}
/** Return an LTLFormula_ptr of the negation of this formula */
public LTLFormula negate()
{
LTLNode new_root = new LTLNode(type_t.T_NOT, getRootNode());
return new LTLFormula(new_root, _apset);
}
/** Copy constructor (not deep) */
public LTLFormula(LTLFormula other)
{
_root = other._root;
_apset = other._apset;
}
/**
* Constructor
* @param root the root node
* @param apset the underlying APSet
*/
public LTLFormula(LTLNode root, APSet apset)
{
_root = root;
_apset = apset;
}
/** Constructor for an operator of type */
public LTLNode(type_t type, LTLNode left, LTLNode right)
{
_type = type;
_left = left;
_right = right;
}
/** Copy constructor (not deep) */
public LTLFormula(LTLFormula other)
{
_root = other._root;
_apset = other._apset;
}
/** Return an LTLFormula_ptr of the negation of this formula */
public LTLFormula negate()
{
LTLNode new_root = new LTLNode(type_t.T_NOT, getRootNode());
return(new LTLFormula(new_root, _apset));
}
public LTLNode toPNF(bool negate)
{
switch (_type)
{
case type_t.T_XOR:
throw new Exception("XOR not yet supported!");
case type_t.T_IMPLICATE:
{
if (negate)
{
// ! (a->b) = !(!a | b) = (a & ! b)
return(new LTLNode(type_t.T_AND, getLeft().toPNF(), getRight().toPNF(true)));
}
else
{
// (a->b) = (!a | b)
return(new LTLNode(type_t.T_OR, getLeft().toPNF(true), getRight().toPNF()));
}
break;
}
case type_t.T_EQUIV:
{
if (negate)
{
// ! (a<->b) == (a & !b) || (!a & b)
return(new
LTLNode(type_t.T_OR,
new LTLNode(type_t.T_AND, getLeft().toPNF(), getRight().toPNF(true)),
new LTLNode(type_t.T_AND, getLeft().toPNF(true), getRight().toPNF())));
}
else
{
// (a<->b) = (!a && !b) || (a && b)
return(new LTLNode(type_t.T_OR,
new LTLNode(type_t.T_AND, getLeft().toPNF(true), getRight().toPNF(true)),
new LTLNode(type_t.T_AND, getLeft().toPNF(), getRight().toPNF())));
}
}
case type_t.T_NOT:
if (negate)
{
// double negation
return(getLeft().toPNF()); ////////////////////?? shouldn't be getRight().toPNF()? !(!a) = a
}
else
{
if (getLeft().getType() == type_t.T_AP)
{
// we are in front of an AP, negation is ok
return(new LTLNode(type_t.T_NOT, getLeft()));
}
else
{
return(getLeft().toPNF(true));
}
}
case type_t.T_AP:
if (negate)
{
return(new LTLNode(type_t.T_NOT, new LTLNode(_ap)));
}
else
{
return(new LTLNode(_ap));
}
case type_t.T_TRUE:
if (negate)
{
return(new LTLNode(type_t.T_FALSE, null));
}
else
{
return(new LTLNode(type_t.T_TRUE, null));
}
case type_t.T_FALSE:
if (negate)
{
return(new LTLNode(type_t.T_TRUE, null));
}
else
{
return(new LTLNode(type_t.T_FALSE, null));
}
case type_t.T_AND:
// ! (a & b) = (!a | !b)
if (negate)
{
return(new LTLNode(type_t.T_OR, getLeft().toPNF(true), getRight().toPNF(true)));
}
else
{
return(new LTLNode(type_t.T_AND, getLeft().toPNF(), getRight().toPNF()));
}
case type_t.T_OR:
if (negate)
{
// ! (a | b) = (!a & !b)
return(new LTLNode(type_t.T_AND, getLeft().toPNF(true), getRight().toPNF(true)));
}
else
{
return(new LTLNode(type_t.T_OR, getLeft().toPNF(), getRight().toPNF()));
}
case type_t.T_NEXTSTEP:
// ! (X a) = X (!a)
if (negate)
{
return(new LTLNode(type_t.T_NEXTSTEP, getLeft().toPNF(true)));
}
else
{
return(new LTLNode(type_t.T_NEXTSTEP, getLeft().toPNF()));
}
case type_t.T_FINALLY:
// ! (F a) = G (!a) = f V !a
if (negate)
{
return(new LTLNode(type_t.T_RELEASE, new LTLNode(type_t.T_FALSE, null), getLeft().toPNF(true)));
}
else
{ // F a = t U a
return(new LTLNode(type_t.T_UNTIL, new LTLNode(type_t.T_TRUE, null), getLeft().toPNF()));
}
case type_t.T_GLOBALLY:
// ! (G a) = F (!a) = t U ! a
if (negate)
{
return(new LTLNode(type_t.T_UNTIL, new LTLNode(type_t.T_TRUE, null), getLeft().toPNF(true)));
}
else
{ // f V a
return(new LTLNode(type_t.T_RELEASE, new LTLNode(type_t.T_FALSE, null), getLeft().toPNF()));
}
case type_t.T_UNTIL:
// ! (a U b) = (!a V !b)
if (negate)
{
return(new LTLNode(type_t.T_RELEASE, getLeft().toPNF(true), getRight().toPNF(true)));
}
else
{
return(new LTLNode(type_t.T_UNTIL, getLeft().toPNF(), getRight().toPNF()));
}
case type_t.T_RELEASE:
// ! (a R b) = (!a U !b)
if (negate)
{
return(new LTLNode(type_t.T_UNTIL, getLeft().toPNF(true), getRight().toPNF(true)));
}
else
{
return(new LTLNode(type_t.T_RELEASE,
getLeft().toPNF(),
getRight().toPNF()));
}
case type_t.T_WEAKUNTIL:
{
LTLNode weak_until = new LTLNode(type_t.T_UNTIL, getLeft(),
new LTLNode(type_t.T_OR, getRight(),
new LTLNode(type_t.T_GLOBALLY, getLeft(), null)));
return(weak_until.toPNF(negate));
}
case type_t.T_WEAKRELEASE:
throw new Exception("Operator WEAKRELEASE not yet supported");
case type_t.T_BEFORE:
throw new Exception("Operator BEFORE not yet supported");
}
throw new Exception("Implementation error");
}
private static LTLNode TranslateLTL(ltl2ba.Node CurrentNode, APSet apset, APSet predefined_apset)
{
if (CurrentNode == null)
{
return(null);
}
type_t nodeType = type_t.T_TRUE;
switch ((Operator)CurrentNode.ntyp)
{
case Operator.ALWAYS:
nodeType = type_t.T_GLOBALLY;
break;
case Operator.AND:
nodeType = type_t.T_AND;
break;
case Operator.EQUIV:
nodeType = type_t.T_EQUIV;
break;
case Operator.EVENTUALLY:
nodeType = type_t.T_FINALLY;
break;
case Operator.FALSE:
nodeType = type_t.T_FALSE;
break;
case Operator.IMPLIES:
nodeType = type_t.T_IMPLICATE;
break;
case Operator.NOT:
nodeType = type_t.T_NOT;
break;
case Operator.OR:
nodeType = type_t.T_OR;
break;
case Operator.TRUE:
nodeType = type_t.T_TRUE;
break;
case Operator.U_OPER:
nodeType = type_t.T_UNTIL;
break;
case Operator.V_OPER:
nodeType = type_t.T_RELEASE;
break;
case Operator.NEXT:
nodeType = type_t.T_NEXTSTEP;
break;
case Operator.PREDICATE:
nodeType = type_t.T_AP;
string ap = CurrentNode.sym.name;
char ch = ap[0];
if (ch == '"')
{
// std::cerr << ap << std::endl;
Debug.Assert(ap[ap.Length - 1] == '"'); // last char is "
if (ap.Length <= 2)
{
// empty ap!
throw new Exception("LTL-Parse-Error: empty quoted string");
}
ap = ap.Substring(1, ap.Length - 2); // cut quotes
}
else if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z'))
{
// nop
}
else
{
throw new Exception("LTL-Parse-Error");
}
int ap_i; // the AP index
if (predefined_apset != null)
{
if ((ap_i = predefined_apset.find(ap)) != -1)
{
return(new LTLNode(ap_i));
}
else
{
// not found in predefined APSet!
//std::cerr << "[" << (int)s[2] << "]" << std::endl;
throw new Exception("Can't parse formula with this APSet!");
}
}
else
{
if ((ap_i = apset.find(ap)) != -1)
{
// AP exists already
return(new LTLNode(ap_i));
}
else
{
// create new AP
ap_i = apset.addAP(ap);
return(new LTLNode(ap_i));
}
}
break;
default:
break;
}
LTLNode newNode = new LTLNode(nodeType, TranslateLTL(CurrentNode.lft, apset, predefined_apset),
TranslateLTL(CurrentNode.rgt, apset, predefined_apset));
return(newNode);
}
private static LTLNode TranslateLTL(ltl2ba.Node CurrentNode, APSet apset, APSet predefined_apset)
{
if (CurrentNode == null)
{
return null;
}
type_t nodeType = type_t.T_TRUE;
switch ((Operator) CurrentNode.ntyp)
{
case Operator.ALWAYS:
nodeType = type_t.T_GLOBALLY;
break;
case Operator.AND:
nodeType = type_t.T_AND;
break;
case Operator.EQUIV:
nodeType = type_t.T_EQUIV;
break;
case Operator.EVENTUALLY:
nodeType = type_t.T_FINALLY;
break;
case Operator.FALSE:
nodeType = type_t.T_FALSE;
break;
case Operator.IMPLIES:
nodeType = type_t.T_IMPLICATE;
break;
case Operator.NOT:
nodeType = type_t.T_NOT;
break;
case Operator.OR:
nodeType = type_t.T_OR;
break;
case Operator.TRUE:
nodeType = type_t.T_TRUE;
break;
case Operator.U_OPER:
nodeType = type_t.T_UNTIL;
break;
case Operator.V_OPER:
nodeType = type_t.T_RELEASE;
break;
case Operator.NEXT:
nodeType = type_t.T_NEXTSTEP;
break;
case Operator.PREDICATE:
nodeType = type_t.T_AP;
string ap = CurrentNode.sym.name;
char ch = ap[0];
if (ch == '"')
{
// std::cerr << ap << std::endl;
Debug.Assert(ap[ap.Length - 1] == '"'); // last char is "
if (ap.Length <= 2)
{
// empty ap!
throw new Exception("LTL-Parse-Error: empty quoted string");
}
ap = ap.Substring(1, ap.Length - 2); // cut quotes
}
else if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z'))
{
// nop
}
else
{
throw new Exception("LTL-Parse-Error");
}
int ap_i; // the AP index
if (predefined_apset != null)
{
if ((ap_i = predefined_apset.find(ap)) != -1)
{
return new LTLNode(ap_i);
}
else
{
// not found in predefined APSet!
//std::cerr << "[" << (int)s[2] << "]" << std::endl;
throw new Exception("Can't parse formula with this APSet!");
}
}
else
{
if ((ap_i = apset.find(ap)) != -1)
{
// AP exists already
return new LTLNode(ap_i);
}
else
{
// create new AP
ap_i = apset.addAP(ap);
return new LTLNode(ap_i);
}
}
break;
default:
break;
}
LTLNode newNode = new LTLNode(nodeType, TranslateLTL(CurrentNode.lft, apset, predefined_apset),
TranslateLTL(CurrentNode.rgt, apset, predefined_apset));
return newNode;
}
