std::vector<KFormula*> KFormula::getAtoms(KFormula* f) {
std::vector<KFormula*> atoms;
std::deque<KFormula*> formulae;
formulae.push_back(f);
while (!formulae.empty()) {
KFormula* formula = formulae.front();
formulae.pop_front();
switch (formula->getop()) {
case KFormula::AP:
atoms.push_back(formula);
break;
case KFormula::BOX:
atoms.push_back(formula);
formulae.push_back(&(formula->getleft()));
break;
case KFormula::NOT:
// Immediately continue with the unnegated formula.
formulae.push_front(&(formula->getleft()));
break;
case KFormula::AND:// Fall through
case KFormula::OR:
// Breadth-first add from both sides.
formulae.push_back(&(formula->getleft()));
formulae.push_back(&(formula->getright()));
break;
case KFormula::TRUE:
break;
case KFormula::FALSE:
break;
case KFormula::DIA:
assert(false && "Atom adding not defined for <>.");
case KFormula::IMP:
assert(false && "Atom adding not defined for =>.");
case KFormula::EQU:
assert(false && "Atom adding not defined for <=>.");
default:
assert(false && "Defaulted out of complete switch");
}
}
return atoms;
}
KFormula* KFormula::parseRest(const char*& str) {
while(isspace(*str)) ++str;
KFormula *left;
if(*str == '('){
++str;
left = parseEQU(str);
while(isspace(*str)) ++str;
assert(*str == ')');
++str;
return left;
} else if (strncmp(str,"<", 1) == 0 && (isalnum(*(str + 1)) || *(str+1) == '-')) {
size_t n = 1;// "<"
if (*(str+1) == '-') ++n;
while(isalnum(*(str+n))) ++n;
std::string roleString(str+1, n - 1);
++n;// ">"
str += n;
left = parseRest(str);
left = new KFormula(KFormula::DIA,left,NULL);
left->setprop(roleString);
return left;
} else if (strncmp(str,"<>", 2) == 0) {
str += 2;
left = parseRest(str);
left = new KFormula(KFormula::DIA,left,NULL);
return left;
} else if (strncmp(str,"[", 1) == 0 && (isalnum(*(str + 1)) || *(str+1) == '-')) {
size_t n = 1;// "["
if (*(str+1) == '-') ++n;
while(isalnum(*(str+n))) ++n;
std::string roleString(str+1, n - 1);
++n;// "]"
str += n;
left = parseRest(str);
left = new KFormula(KFormula::BOX,left,NULL);
left->setprop(roleString);
return left;
}else if (strncmp(str,"[]",2) == 0) {
str += 2;
left = parseRest(str);
left = new KFormula(KFormula::BOX,left,NULL);
return left;
} else if (*str=='~') {
++str;
left = parseRest(str);
left = new KFormula(KFormula::NOT,left,NULL);
return left;
} else if (strncmp(str,"True",4)==0) {
str += 4;
return new KFormula(true);
} else if (strncmp(str,"False",5)==0) {
str += 5;
return new KFormula(false);
} else if (isalpha(*str) || *str == '_') {
size_t n = 1;
while(isalnum(*(str+n)) || *(str+n) == '_') ++n;
left = new KFormula(std::string(str,n));
str += n;
return left;
}
assert(false && "Could not parse input");
// Must not reach here
}
/*
* BoxNNF: NNF with the following exceptions:
* BoxNNF(~[]phi) = ~BoxNNF([]phi)
* BoxNNF(<>phi) = ~[]BoxNNF(~phi)
* This is to normalise the modalities so that we don't get separate BDD
* variables for <>~phi and []phi. These should share the same variable,
* as ~<>~phi = []phi.
*/
KFormula* KFormula::toBoxNNF(KFormula* f) {
switch (f->getop()) {
case KFormula::AP:
return f;
case KFormula::AND:
return new KFormula(KFormula::AND, toBoxNNF(&(f->getleft())), toBoxNNF(&(f->getright())));
case KFormula::OR:
return new KFormula(KFormula::OR, toBoxNNF(&(f->getleft())), toBoxNNF(&(f->getright())));
case KFormula::BOX:
{KFormula* tmpf = new KFormula(KFormula::BOX, toBoxNNF(&(f->getleft())), NULL);
tmpf->setprop(f->getprop());
return tmpf;}
case KFormula::DIA:// BoxNNF(<>phi) = ~[]BoxNNF(~phi)
{KFormula* tmpf = new KFormula(KFormula::BOX,
toBoxNNF(new KFormula(KFormula::NOT,
&(f->getleft()),
NULL)),
NULL);
tmpf->setprop(f->getprop());// TODO this multimodal hack is really ugly...
return new KFormula(KFormula::NOT,
tmpf,
NULL);}
case KFormula::TRUE:
return f;
case KFormula::FALSE:
return f;
case KFormula::IMP:
return toBoxNNF(new KFormula(KFormula::OR, new KFormula(KFormula::NOT, &(f->getleft()), NULL), &(f->getright())));
case KFormula::NOT:
switch (f->getleft().getop()) {
case KFormula::AP:
return f;
case KFormula::AND:
return new KFormula(KFormula::OR,
toBoxNNF(new KFormula(KFormula::NOT, &(f->getleft().getleft()), NULL)),
toBoxNNF(new KFormula(KFormula::NOT, &(f->getleft().getright()), NULL)));
case KFormula::OR:
return new KFormula(KFormula::AND,
toBoxNNF(new KFormula(KFormula::NOT, &(f->getleft().getleft()), NULL)),
toBoxNNF(new KFormula(KFormula::NOT, &(f->getleft().getright()), NULL)));
case KFormula::BOX:// BoxNNF(~[]phi) = ~[]BoxNNF(phi)
{KFormula* tmpf = new KFormula(KFormula::BOX,
toBoxNNF(&(f->getleft().getleft())), NULL);
tmpf->setprop(f->getleft().getprop());
return new KFormula(KFormula::NOT,
tmpf,
NULL);}
case KFormula::DIA:
{KFormula* tmpf = new KFormula(KFormula::BOX,
toBoxNNF(new KFormula(KFormula::NOT, &(f->getleft().getleft()), NULL)),
NULL);
tmpf->setprop(f->getleft().getprop());
return tmpf;}
case KFormula::TRUE:
return new KFormula(false);
case KFormula::FALSE:
return new KFormula(true);
case KFormula::IMP:
return toBoxNNF(new KFormula(KFormula::AND, &(f->getleft().getleft()), new KFormula(KFormula::NOT, &(f->getleft().getright()), NULL)));
case KFormula::NOT:
return toBoxNNF(&(f->getleft().getleft()));
case KFormula::EQU:
return new KFormula(KFormula::AND,
new KFormula(KFormula::OR,
toBoxNNF(new KFormula(KFormula::NOT, &(f->getleft().getleft()), NULL)),
toBoxNNF(new KFormula(KFormula::NOT, &(f->getleft().getright()), NULL))),
new KFormula(KFormula::OR,
toBoxNNF(&(f->getleft().getleft())),
toBoxNNF(&(f->getleft().getright()))));
default:
assert(false && "Defaulted out of complete switch.");
}
case KFormula::EQU:
return new KFormula(KFormula::OR,
new KFormula(KFormula::AND,
toBoxNNF(&(f->getleft())),
toBoxNNF(&(f->getright()))),
new KFormula(KFormula::AND,
toBoxNNF(new KFormula(KFormula::NOT, &(f->getleft()), NULL)),
toBoxNNF(new KFormula(KFormula::NOT, &(f->getright()), NULL))));
default:
assert(false && "Defaulted out of complete switch.");
}
exit(0);
}
