I was reading the basic dictionary of Japanese grammar, an entry on が to be exact, and they used this interesting example sentence:
and translated it as "I'm running, but I haven't lost any weight at all".
Why is "yasemasen" used here? The Genki textbook says that the English "haven't done X" constructions normally translate to "~ていません", which is obviously not the case here. Is it maybe because the sentence is actually habitual or something? I.e. it doesn't mean "I'm running right now at the moment of speaking", but rather "I run periodically but I'm not (habitually) losing any weight", or in Russian, "Бегаю, но совсем не худею"? Is this what this sentence means?