fix λ.. printing and test it

See merge request !51

Make trivial instances explicit

See merge request !50

This is in preparation for coq/coq#9274.

`tc_to_bool` to turn a type class into a Boolean that expresses if there is an instance

See merge request !48

Add results about deleting and inserting filtered out elements

See merge request !46

Get rid of the awk.Makefile references

See merge request !47

Two reasons:

- The equality makes it very hard to use the lemma with `rewrite`.
- The version for lists `insert_zip_with` does not have the equality either.

Add link to docs to the Readme

See merge request !42

Explicitly use core hint database

See merge request !43

Adding a hint without a database now triggers a deprecation warning in
Coq master (https://github.com/coq/coq/pull/8987).

- Interaction with delete
- Make name about map interacting with insert consistent.

MR #41 relies on https://github.com/coq/coq/issues/5039, which has
not been fixed in Coq 8.6.

Consistently block `simpl` on all `Z` operations

See merge request !41