zkutch

iNow Thanks for answer, you are right. Obviously I forgot refreshing, maybe, because this is my 1-st theme here. Sensei. Thanks. Editing post has restricted time or writing? And question: can I delete post? how? can I move it to something like sendbox (how)? Is there somebody written doc about these everything?

Thanks, but [math] tags gave me nothing - I choose also "insert code" and experiment with "HTML", "STEX/LATEX" , but again no success.. [math] x \in X [/math]

Tried to insert Tex formula, but without success. Sorry, but how to write here tex formulas and how to delete topic? n \in N