About the version upgrade
Mizar versions are frequently updated. At this time, the increase of a library is natural and the check of its article under description is not affected, but we require care about a checker's version upgrade. Please watch the homepage of MIZAR on the Internet frequently and take care to get the newest.
Sometimes, the basic theorem which was being used before will be canceled and we may be puzzled. In this case, the information is written in the file in the directory of a new version. The name of this file is the following.