hustmphrrr / dot-ott

Ott formalization of the DOT calculus

DOT in Ott

To run, ensure that the following are installed, then run ./build.sh

metalib

Ensure that you have Coq installed.

cd Metalib
make
make install

Metalib was modified in one place to fix a broken tactic.

lngen

Ensure that you have stack installed.

stack install

Lngen was only modified to replace Require Export Metatheory with Require Export Metalib.Metatheory as per the current naming conventions in metalib.

ott

make world
ln -s $(pwd)/bin/ott /user/local/bin/

Ott was modified to properly handle non-recursive rules referencing metavariables.

Remaining Work

lngen does not know how to generate the correct code for multiple bind statements, which means that the production rule

val :: 'val_' ::=
  | nu ( x : T ) defs :: :: new (+ bind x in defs+)

is currently incorrect since x should also be bound in T. Adding a second (+ bind x in T +) clause will cause Ott to generate the correct code, but raises a warning saying that lngen does not support this. Indeed, lngen will fail when encountering a production rule with 2 binds. The main consequence of that judgements that look like

( G , x : T ) |- defs : T
------------------------------------- :: new_intro
G |- nu ( x : T ) defs : mu ( x : T )

will incorrectly translate, since x is not bound to T, as

 | ty_new_intro : forall (L:vars) (G:ctx) (T:typ) (defs5:defs),
      ( forall x , x \notin  L  -> ty_defs  ( x ~  ( open_typ_wrt_varref T (var_termvar_f x) )   ++  G )   ( open_defs_wrt_varref defs5 (var_termvar_f x) )   ( open_typ_wrt_varref T (var_termvar_f x) )  )  ->
      ( forall x , x \notin  L  -> ty_trm G (trm_val (val_new  ( open_typ_wrt_varref T (var_termvar_f x) )  defs5)) (typ_bnd T) ) 

note the unnecessary second cofinite quantification, which does not occur if we add (+ bind x in T +).

lngen will sometimes generate incorrect code code by silently failing on naming conflicts, for example in the production rule

v1 v2 :: :: app

changing this rule to be

vx vy :: :: app

while adding the appropriate aliases to varref will cause lngen to generate incorrect code.