static ValueTypes UseType(Racr.AstNode n) { return n.GLookup(n.GetName()).Type(); }
static Racr.AstNode ElementFindActive(Racr.AstNode n, string name) {
var current = n.GLookup(name);
while (!current.IsActive()) current = current.GLookup(name);
return current;
}
static bool QuestionIsLValid(Racr.AstNode n) {
if (n.Type() == ValueTypes.ErrorType) return false;
var prev = n.GLookup(n.GetName());
return prev.IsErrorQuestion() || n.Type() == prev.Type();
}