On Wed, 21 Jan 1998, Piotr Rudnicki wrote: > Long time ago I have sent a question to mus and never got nay answer. So sorry! My fault. Because you had written that you want to discuss the topic on mizar-forum, I supossed that you would send the message here. So I told Grzegorz to wait. You'll be answered right away. Andrzej Trybulec