I have seen experienced users and moderators comment on some questions that cs stackexchange does not support yes/no type questions ( not the exact words ). But if the OP discusses his/her approach and is not able to prove it thoroughly and asks whether what he/she is trying to prove if correct or not, is it still discouraged ? By yes/no type questions I mean where OP discusses his/her approach and asks if its correct. Although the answer might be a "yes" followed by the complete proof, it is still adding to stackexchange's resource, provided the question or OP's approach is good.
It's in particular the "please check that I will get full credit on my homework"-flavor we don't like. This site is for answering questions, neither reviewing work not building a repository of homework problems and solutions.
Also, we think that a focused question about the approach, highlighting the specific doubt the OP has, makes for a much better question. If there is no such doubt, the question should never have been posted -- because there is no question.
Of course, this has been discussed before; see