negOp = NEGATIONOPERATORS.get(negOpSym.getSymbol());
}
if(negSym.tryParse(st))
neg = true;
try {
NonGroundPredicate p = new PredicateParser().parse(st);
return new NonGroundLiteral(p,neg,naf,negOp);
} catch (ParseException e) {
throw new ParseException(st,"failed to parse literal: "+e.getMessage());
}
}