A simple representation of LF in LF.  This comes in a declarative and an
executable (type-checking) flavor.  The encoding leaves signatures and
contexts implicit, which means that signatures have to be translated.
Unfortunately it also means that type-checking rules etc. have to be
extended to apply to the new constants!

As a non-trivial examples, the files fol-* contain the representation of
an LF signature for first-order logic in the encoding.

Author: Frank Pfenning

