1. Myhill.thy is proved to correct some typos. 2. Some sections are added to the first direction. 3. The small theory of list difference is now separated into Prefix_subtract.thy and the ROOT.ML
\BOOKMARK [1][-]{section.1}{Preliminary definitions}{}
\BOOKMARK [1][-]{section.2}{Direction finite partition \040regular language}{}
\BOOKMARK [2][-]{subsection.2.1}{Proof for this direction}{section.2}
\BOOKMARK [1][-]{section.3}{Direction: regular language finite partition}{}
\BOOKMARK [2][-]{subsection.3.1}{The scheme for this direction}{section.3}
\BOOKMARK [2][-]{subsection.3.2}{A small theory for list difference}{section.3}
\BOOKMARK [2][-]{subsection.3.3}{Lemmas for basic cases}{section.3}
\BOOKMARK [2][-]{subsection.3.4}{The case for SEQ}{section.3}
\BOOKMARK [2][-]{subsection.3.5}{The case for ALT}{section.3}
\BOOKMARK [2][-]{subsection.3.6}{The case for STAR}{section.3}
\BOOKMARK [2][-]{subsection.3.7}{The main lemma}{section.3}