Fix in preparation for https://github.com/coq/coq/pull/13188

Tej Chajed authored 4 years ago and Robbert Krebbers committed 4 years ago

Set Default Goal Selector "!" makes it illegal to ever apply a tactic
with more than one goal (instead, must focus with bullets or braces).

This follows iris/iris!387
This closes issue #54.

Due to Coq bug #10480 or #10474 it actually used `Morphisms.solve_proper`
instead of the version of std++. The version in std++ can inherently
not solve this, so I changed it into a manual proof.

- The class `Infinite A` is now defined as having a function
  `fresh : list A → A`, that given a list `xs`, gives an element `x ∉ xs`.
- For most types this `fresh` function has a sensible computable behavior,
  for example:
  + For numbers, it yields one added to the maximal element in `xs`.
  + For strings, it yields the first string representation of a number that is
    not in `xs`.
- For any type `C` of finite sets with elements of infinite type `A`, we lift
  the fresh function to `C → A`.

As a consequence:

- It is now possible to pick fresh elements from _any_ finite set and from
  _any_ list with elements of an infinite type. Before it was only possible
  for specific finite sets, e.g. `gset`, `pset`, ...
- It makes the code more uniform. There was a lot of overlap between having a
  `Fresh` and an `Infinite` instance. This got unified.

Get rid of using `Collection` and favor `set` everywhere. Also, prefer conversion
functions that are called `X_to_Y`.

The following sed script performs most of the renaming, with the exception of:

- `set`, which has been renamed into `propset`. I couldn't do this rename
  using `sed` since it's too context sensitive.
- There was a spurious rename of `Vec.of_list`, which I correctly manually.
- Updating some section names and comments.

```
sed '
s/SimpleCollection/SemiSet/g;
s/FinCollection/FinSet/g;
s/CollectionMonad/MonadSet/g;
s/Collection/Set\_/g;
s/collection\_simple/set\_semi\_set/g;
s/fin\_collection/fin\_set/g;
s/collection\_monad\_simple/monad\_set\_semi\_set/g;
s/collection\_equiv/set\_equiv/g;
s/\bbset/boolset/g;
s/mkBSet/BoolSet/g;
s/mkSet/PropSet/g;
s/set\_equivalence/set\_equiv\_equivalence/g;
s/collection\_subseteq/set\_subseteq/g;
s/collection\_disjoint/set\_disjoint/g;
s/collection\_fold/set\_fold/g;
s/collection\_map/set\_map/g;
s/collection\_size/set\_size/g;
s/collection\_filter/set\_filter/g;
s/collection\_guard/set\_guard/g;
s/collection\_choose/set\_choose/g;
s/collection\_ind/set\_ind/g;
s/collection\_wf/set\_wf/g;
s/map\_to\_collection/map\_to\_set/g;
s/map\_of\_collection/set\_to\_map/g;
s/map\_of\_list/list\_to\_map/g;
s/map\_of\_to_list/list\_to\_map\_to\_list/g;
s/map\_to\_of\_list/map\_to\_list\_to\_map/g;
s/\bof\_list/list\_to\_set/g;
s/\bof\_option/option\_to\_set/g;
s/elem\_of\_of\_list/elem\_of\_list\_to\_set/g;
s/elem\_of\_of\_option/elem\_of\_option\_to\_set/g;
s/collection\_not\_subset\_inv/set\_not\_subset\_inv/g;
s/seq\_set/set\_seq/g;
s/collections/sets/g;
s/collection/set/g;
' -i $(find -name "*.v")
```

This makes some proress on #21. Still, the question remains if a more
generic solution exists.

Also make the instances non-global, to prevent multiple instance
problems.

This implements a simple linear search for fresh elements.

This allows for more control over `Hint Mode`.

This provides significant robustness against looping type class search.

As a consequence, at many places throughout the library we had to add
additional typing information to lemmas. This was to be expected, since
most of the old lemmas were ambiguous. For example:

  Section fin_collection.
    Context `{FinCollection A C}.

    size_singleton (x : A) : size {[ x ]} = 1.

In this case, the lemma does not tell us which `FinCollection` with
elements `A` we are talking about. So, `{[ x ]}` could not only refer to
the singleton operation of the `FinCollection A C` in the section, but
also to any other `FinCollection` in the development. To make this lemma
unambigious, it should be written as:

  Lemma size_singleton (x : A) : size ({[ x ]} : C) = 1.

In similar spirit, lemmas like the one below were also ambiguous:

  Lemma lookup_alter_None {A} (f : A → A) m i j :
    alter f i m !! j = None  m !! j = None.

It is not clear which finite map implementation we are talking about.
To make this lemma unambigious, it should be written as:

  Lemma lookup_alter_None {A} (f : A → A) (m : M A) i j :
    alter f i m !! j = None  m !! j = None.

That is, we have to specify the type of `m`.

This fixes issue #65.

Rename:

- prefix_of -> prefix and suffix_of -> suffix because that saves keystrokes
  in lemma names. However, keep the infix notations with l1 `prefix_of` l2 and
  l1 `suffix_of` l2 because those are easier to read.
- change the notation l1 `sublist` l2 into l1 `sublist_of` l2 to be consistent.
- rename contains -> submseteq and use the notation ⊆+

This patch was created using

  find -name *.v | xargs -L 1 awk -i inplace '{from = 0} /^From/{ from = 1; ever_from = 1} { if (from == 0 && seen == 0 && ever_from == 1) { print "Set Default Proof Using \"Type*\"."; seen = 1 } }1 '

and some minor manual editing