Literate Programming Using Noweb  Noweb is a tool designed to
enable a programmer to write documentation and code at the same
time, with the goal of producing code that is easy to understand
and maintain. Writing the Program in Noweb  With the knowledge
of what comes out the end of the pipeline in hand, we can now
describe the structure of the nw source file itself. The nw
source file for our example program is given in Listing 1.  When
you write a noweb program, you alternate between explaining some
piece of code and providing the formal definition of that piece
of code. You must indicate whether you are entering
documentation or code by using one of two noweb tags.  To begin
writing documentation, one starts with an @ symbol in the left
column, followed by either a space or a newline. This indicates
that all of the text that follows, at least up to the next tag,
is documentation text. All documentation text is passed through
the filtering process to the (LA)TeX file. Thus, the author is
responsible for prov