GitLab

- move exception reporting for Ty, Pattern, Term, and Decl
  to Pretty, as it occasionnaly requires some pretty-printing

I will always compile before committing
I will always compile before committing
I will...

like f_map_sign should only be applied from specialized
recursive functions and these funcitons will usually supply
the polarity argument.

It's not more expressive but much nicer than epsilon.

  as it is most often ignored
- check for empty map in t_subst/f_subst
- bugfix: don't forget nested match statements in Decl and Compile_match

- check pattern well-formedness in Pattern
- add arguments to exceptions in Ty and Term

(unusable so far, must eliminate match statements, too)

for uniquely tagged objects.

the underlying term/fmla is not changed

- unify Lfunction and Lpredicate (mucho bettar)
- separation of prop and fmla
- making prop and tvsymbol private aliases of ident

- move redefinition of f_app higher in Term
  to make sure that ps_neq can never appear
- if a user "instantiates" a lemma as a goal on cloning, 
  the lemma just disappears (as it is alredy proved)
- catch Not_found in merge_namespace on cloning,
  due to local goals not being cloned

to build an ill-typed formula. Unsafe functions are actually unsafe.

This is less dangerous than I previously thought,
because we still can never create an ill-typed term,
nor we can push a term with an unprotected de Bruijn
index into a context. Salut, François ;)