This module contains parser library independent code which can be used to describe inlerleaved execution of applicative style structures. It is amongst other used in the uu-options package, which provides facilities for parsing command-line options or files containing preferences. It generalises the permuting parsers and the list merging parsers as e.g. found in the uulib library. For a more complete description see the Technical Report describing its implementation and use see http://www.cs.uu.nl/research/techreps/UU-CS-2013-005.html.