
    This directory contains the trailers, which are generated at Flora
    build time by combining the templates in headerinc/
    This dir contains only .P files, which are all cleaned up by make clean.

How trailers are used:

1. Trailers in closure/ are included in compiled program.
2. Trailers in trailer/ are compiled for module main and are dynamically
   loaded in the shell when it starts.
3. Trailers in .xsb/flora/ are compiled dynamically for the appropriate
   module when an executable instruction ?- equality ... [in module]
   is executed.

Instead of mechanism (1), we could have used (3), but (1) is going to
give a slightly better time for loading. At the expense of having worse
compile time because XSB has to compile the trailers for multiple modules
multiple times.
