GitLab

In the interpretation of recursive types

- rename `bin_log_related_bind_l` to `bin_log_related_wp_l`
- use `bin_log_related_wp_l` to simplify derived rules

Using the lambdasubst hack-- instead of formulating
lemmas for (App e1 v), formulate them for (e1[x:=v]).

..by introducing a hint database for typeability

- Make sure that arguments to the lemmas are in the consistent order:
\Gamma, E1, E2, K, e1, e2, \tau -- from left to right, as you write it
 on paper
- Add masks to all the lemmas
- Add missing rules
- Remove unnecessary closedness conditions

It can be deduce from [head_reducible e], since values are non-reducible.

- Remove commented out code
- Pull std++ related lemmas into a separate file

In this file I will keep all the comments regarding different aspects
of formalisation.

The current prove does not reuse certain lemmas

Following the advice of Amin Timany
generalize all the compatibility lemmas
at the same time by declaring a mask E in a Section.

We are switich away from De Bruijn indices because
1) it's hard to read terms with De Bruijn indices
2) they are making lots of things slower

And improve the proof of the fundamental property

The new _with_lock rule does not mentioned lower level details of the
relational interpretation.