re detecting and switching language: you could run several constraint systems in parallel and switch as soon as one of them rejects the input and another accept

re detecting and switching language: you could run several constraint systems in parallel and switch as soon as one of them rejects the input and another accepts it re backtracking: a core part of this paper is ensuring a prefix property. that is there is always a legitimate completion and the model can not "corner" itself! research needs to be done for what kind of languages and language features this prefix property can be ensured