unless + negation

[allthewayanime]

I have got a big doubt about concerning this topic: if 'unless' can be followed by a negative form.
My understanding is that I can use the negative form after unless(with the meaning of 'if not'), only that the meaning of the sentence introduced by unless will turn out to have a positive signification. Could someone confirm it or not,please?

e.g. Unless he doesn't do his homework, he's free to play computer games.
It means that if he does his homework , he will be free to play....

 

[5jj]

e.g. Unless he doesn't do his homework, he's free to play computer games.
It means that if he does his homework , he will be free to play....

To a certain extent, yes. 'Unless' and 'if not' are not exactly synonyms - 'unless' has more of the idea of 'only if... not'.