michael/lean2
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
Mirror of https://github.com/leanprover/lean2 in case it ever disappears
948 commits 3 branches 0 tags 28 MiB
C++ 47.8%
Lean 41.8%
JetBrains MPS 5.4%
Emacs Lisp 2.1%
C 1%
Other 1.7%
Find a file
Leonardo de Moura 4dd6cead83 refactor(equality): make homogeneous equality the default equality 
It was not a good idea to use heterogeneous equality as the default equality in Lean.
It creates the following problems.

- Heterogeneous equality does not propagate constraints in the elaborator.
For example, suppose that l has type (List Int), then the expression
     l = nil
will not propagate the type (List Int) to nil.

- It is easy to write false. For example, suppose x has type Real, and the user
writes x = 0. This is equivalent to false, since 0 has type Nat. The elaborator cannot introduce
the coercion since x = 0 is a type correct expression.

Homogeneous equality does not suffer from the problems above.
We keep heterogeneous equality because it is useful for generating proof terms.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-10-29 16:20:06 -07:00
doc doc(coding_style): add how to organize template source code 2013-10-28 11:31:46 -04:00
examples/lean Fix typo 2013-09-05 19:18:55 -07:00
script fix(script/demangle_cpptype): process line-by-line, instead of waiting for EOF 2013-09-29 18:36:01 -07:00
src refactor(equality): make homogeneous equality the default equality 2013-10-29 16:20:06 -07:00
tests/lean refactor(equality): make homogeneous equality the default equality 2013-10-29 16:20:06 -07:00
.gitignore Add more tests 2013-08-31 18:46:18 -07:00
.travis.osx.yml chore(travis): use demangle_cpptype.py to print out test/valgrind output 2013-09-29 16:30:02 -07:00
.travis.windows.yml chore(travis): fix git-commit-msg extraction 2013-09-28 13:33:13 -07:00
.travis.yml chore(travis): use demangle_cpptype.py to print out test/valgrind output 2013-09-29 16:30:02 -07:00
LICENSE Add LICENSE file 2013-07-15 18:55:48 -07:00
README.md doc(commit_convention): add git commit_convention 2013-09-25 19:45:15 -07:00

README.md

Build Status Ubuntu 12.04 LTS 64bit, g++-4.8 | clang++-3.3

Build Status Mac OS X 10.8.2, g++-4.9

Build Status Windows, x86_64-w64-mingw32-g++-4.8.1

[Result of Build/UnitTest/Coverage/Dynamic Analysis]

About

Requirements

Installing required packages at

Build Instructions

Miscellaneous