final NodeListOptional orFormulas = (NodeListOptional) ((List<INode>) n.f0.choice
.accept(this, argu)).get(2);
final Disjunction disj = new Disjunction();
disj.setParent(argu);
for (final INode node : (List<INode>) orFormulas.accept(this, disj))
disj.addExpr((IExpression) node.accept(this, disj));
return disj;
case 2:
final List<INode> existINodes = (List<INode>) n.f0.choice.accept(
this, argu);
final ExistExpression exists = new ExistExpression();