lean4-htt

Lean 4 fork for HoTT-compatible kernel extensions (Path types, transport, HITs). Maintained against upstream leanprover/lean4.

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Leonardo de Moura b76deb4f0d fix(tests/playground/parser/syntax): another issue with float `let` inwards @kha I keep finding problems with the float `let` inwards transformation. It is always a nasty interaction between this transformation and the `reset/reuse` insertion procedure. The example I used in the new comment can be modified to a `casesOn` with more than one branch (e.g., `Option.casesOn`). Suppose we wrote ``` let o : Option Nat := Array.index a i in let a := Array.update a i none in Option.casesOn o none (fun n, some (Array.update a i (some (n + 1)))) ``` In the example above, the compiler will float `a := Array.update a i none` inwards. ``` let o : Option Nat := Array.index a i in Option.casesOn o none (fun n, let a := Array.update a i none in some (Array.update a i (some (n + 1)))) ``` Then, adding reset/reuse: ``` let o : Option Nat := Array.index a i in Option.casesOn o none (fun n, let o := reset o in let a := Array.update a i none in let n := n + 1 in let o := reuse o (some n) some (Array.update a i o)) ``` Similarly to the example in the new comment, the `reset o` will fail since the array `a` would still have a reference to `o`. Remarks: - Haskell also implements float `let` inwards. - I am not sure how important the float `let` inward transformation is. - I can see other nasty interactions after we implement user-defined simplification rules. For example, I guess many users would find the following lemma to be a good rewriting rule: ``` (Array.update (Array.update a i v) i w) = (Array.update a i w) ``` However, if we use this lemma in the example above, then `Array.update a i none` will be eliminated, and `reset o` will fail.		2019-04-19 14:52:52 -07:00
.github	chore(.github/CONTRIBUTING): fix typos and URLs	2017-10-30 16:23:22 +01:00
bin	chore(bin/leanc.in): remove flags that do not exist on clang++ for OSX	2019-03-18 08:38:50 -07:00
doc	doc(doc/make/index): add instructions for invoking makefile manually	2019-03-25 14:57:57 -07:00
gen	feat(runtime): avoid extra `switch`	2019-02-23 17:35:21 -08:00
images	chore(CMakeLists.txt): move Lean logo to make sure we can test leanemacs without installing Lean	2015-01-31 17:38:49 -08:00
lean4-mode	feat(frontends/lean): add `partial` keyword	2019-03-26 16:09:55 -07:00
library	chore(library/init/data/array/basic): missing `[inline]`	2019-04-19 14:52:52 -07:00
script	chore(library/constants.txt): remove dead variables	2019-03-22 13:26:48 -07:00
src	fix(tests/playground/parser/syntax): another issue with float `let` inwards	2019-04-19 14:52:52 -07:00
tests	chore(tests/playground): fix tests	2019-04-18 17:29:49 -07:00
.appveyor.yml	chore(.appveyor,.travis): disable leanpkg registry tests	2018-04-12 18:32:20 +02:00
.clang-format	feat(library/vm/process): add basic process support	2017-03-28 18:08:06 -07:00
.codecov.yml	fix(.codecov.yml): do not fail github ci if coverage drops by 0.01%	2017-06-25 10:35:02 +02:00
.gitattributes	chore(.gitattributes): use `union` merge strategy for doc/changes.md	2017-12-11 12:49:10 +01:00
.gitignore	feat(bin/leanc): add simple C++ compiler wrapper script	2019-03-18 16:11:30 +01:00
.travis.yml	chore(.travis.yml): trigger AppVeyor nightly build from Travis	2018-04-13 16:44:27 +02:00
LICENSE	Add LICENSE file	2013-07-15 18:55:48 -07:00
README.md	chore(README): point CI links to lean4 branch	2018-04-12 13:50:42 +02:00