michael/lean2
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
1399 commits 3 branches 0 tags 28 MiB
Commit graph

211 commits

Author SHA1 Message Date
Leonardo de Moura
09bc7ddf91 feat(library/tactic): add support for migratic tactic framework object between Lua states 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-28 08:03:05 -08:00
Leonardo de Moura
3dc7a856f0 refactor(library/tactic): use unprotect/protect idiom for callbacks in the tactic API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-27 18:11:46 -08:00
Leonardo de Moura
b4a8418d38 feat(library/tactic): expose tactics in the Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-27 17:47:29 -08:00
Leonardo de Moura
0934d7b2f4 fix(frontends/lua): make sure Lua 'sleep' function support interruption 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-27 13:25:06 -08:00
Leonardo de Moura
d87ad9eb7e refactor(util/lua): propagate C++ Lean exceptions in Lua 
The following call sequence is possible:
C++ -> Lua -> C++ -> Lua -> C++

The first block of C++ is the Lean main function.
The main function invokes the Lua interpreter.
The Lua interpreter invokes a C++ Lean API.
Then the Lean API invokes a callback implemented in Lua.
The Lua callback invokes another Lean API.
Now, suppose the Lean API throws an exception.
We want the C++ exception to propagate over the mixed C++/Lua call stack.
We use the clone/rethrow exception idiom to achieve this goal.

Before this commit, the C++ exceptions were converted into strings
using the method what(), and then they were propagated over the Lua
stack using lua_error. A lua_error was then converted into a lua_exception when going back to C++.
This solution was very unsatisfactory, since all C++ exceptions were being converted into a lua_exception, and consequently the structure of the exception was being lost.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-27 12:25:29 -08:00
Leonardo de Moura
99a811a586 feat(bindings/lua): expose io_state object in the Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-26 12:54:47 -08:00
Leonardo de Moura
861be072d8 feat(bindings/lua): add proof_state to Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-26 11:34:58 -08:00
Leonardo de Moura
fd3b9e39f6 feat(bindings/lua): add cex_builder to Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-26 09:17:57 -08:00
Leonardo de Moura
4d9075bdfd feat(bindings/lua): add proof_map, assignment and proof_builder to Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-26 08:37:37 -08:00
Leonardo de Moura
3ebc099ec5 feat(bindings/lua/options): improve options Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-25 21:05:05 -08:00
Leonardo de Moura
feeb6d9105 feat(bindings/lua): add goal object to Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-25 20:51:47 -08:00
Leonardo de Moura
7b8bd97699 feat(lua/expr): add method for extracting semantic attachment data 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-19 19:06:47 -08:00
Leonardo de Moura
a98fdd9be6 refactor(shell): combine lean and leanlua executables in a single executable 
The main motivation is to allow users to configure/extend Lean using .lua files before loading the actual .lean files.
Example:
        ./lean extension1.lua extension2.lua file.lean

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-19 16:48:21 -08:00
Leonardo de Moura
87775cbc07 chore(build): include incorrect output in the logs 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-18 15:39:55 -08:00
Soonho Kong
20756c382c test(*): split leantests, leanslowtests, leanluatests, leanluadocs into singletons 2013-11-18 18:27:11 -05:00
Leonardo de Moura
b2d1acd0b7 test(lua/environment): add missing tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-18 09:27:46 -08:00
Leonardo de Moura
1315378ebb test(*): add missing tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-18 09:13:34 -08:00
Leonardo de Moura
7976937e4c test(lua/metavar_env): add missing tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-17 19:18:47 -08:00
Leonardo de Moura
69be5f6c94 feat(kernel/environment): track which modules were already imported 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-17 18:15:44 -08:00
Leonardo de Moura
5f651d46e6 tests(lua/frontend_lean): add missing tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-17 13:48:29 -08:00
Leonardo de Moura
df94e44806 test(lua/expr): add missing tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-17 11:46:24 -08:00
Leonardo de Moura
e693c2de01 test(lua/name): add missing tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-17 11:25:21 -08:00
Leonardo de Moura
8a13df3ce1 test(lua/type_inferer): add missing tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-17 11:17:32 -08:00
Leonardo de Moura
f586e58ac3 test(lua/justification): add more tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-17 11:13:10 -08:00
Leonardo de Moura
d0bac61e74 fix(lua/numerics): bug in bindings, add more tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-17 11:02:44 -08:00
Leonardo de Moura
926ed0a02d feat(lua): add type_inferer object to Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-16 19:18:15 -08:00
Leonardo de Moura
590b14570f feat(lua): improve error handling in Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-16 18:21:42 -08:00
Leonardo de Moura
390f7eaec8 test(kernel/typechecker): type checker 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-16 15:01:39 -08:00
Leonardo de Moura
9398ea5a59 feat(util/shared_mutex): add support for recursive lock at shared_mutex 
We need support for recursive locks. The main user of this class is
the environment object. This commit adds a test that demonstrates that
the shared_lock of the environment object may be recursively requested.
Before this fix, the Lean was deadlocking in this example.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-15 22:01:11 -08:00
Leonardo de Moura
209a2d10f7 fix(lua): replace std::mutex with std::recursive_mutex, add test that demonstrates the problem that is being fixed 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-15 21:26:16 -08:00
Leonardo de Moura
8525e8534b feat(lua): expose parse_expr and parse_commands from frontends/lean in the Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-15 16:11:26 -08:00
Leonardo de Moura
a74412963a chore(build): only execute lua multi-threading tests when on cygwin or linux, and using g++ 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-15 09:27:58 -08:00
Leonardo de Moura
5e170ce5fe chore(tests/lua): move examples that use threads to tests/lua/threads 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-15 09:11:58 -08:00
Leonardo de Moura
b5dcb93550 feat(lua): communication channels for threads 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 21:10:46 -08:00
Leonardo de Moura
3a924a5fb1 perf(lua/name): improve to_name_ext performance 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 18:06:09 -08:00
Leonardo de Moura
45858d54ae test(frontends/lean): add missing expected output 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 15:51:47 -08:00
Leonardo de Moura
6b30ebab5e test(lua): use simplified Const creation 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 15:17:00 -08:00
Leonardo de Moura
09bed4786c feat(lua): add semantic attachments for builtin arithmetical values to Lua API, improve mk_constant 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 15:15:04 -08:00
Leonardo de Moura
abe93dfec0 fix(lua/splay_tree): for_each method was crashing if the map was updated during for_each 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 13:48:23 -08:00
Leonardo de Moura
64cce595a5 feat(lua): add splay_maps to the Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 13:35:36 -08:00
Leonardo de Moura
9e445d1917 feat(lua): interrupt and sleep Lua APIs 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 10:04:32 -08:00
Leonardo de Moura
691893258d feat(kernel/expr): add hash code based on allocation time 
The new hash code has the property that given expr_cell * c1 and expr_cell * c2,
if c1 != c2 then there is a high propbability that c1->hash_alloc() != c2->hash_alloc().

The structural hash code hash() does not have this property because we may have
c1 != c2, but c1 and c2 are structurally equal.

The new hash code is only compatible with pointer equality.
By compatible we mean, if c1 == c2, then c1->hash_alloc() == c2->hash_alloc().
This property is obvious because hash_alloc() does not have side-effects.

The test tests/lua/big.lua exposes the problem fixed by this commit.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-14 02:43:11 -08:00
Leonardo de Moura
ae7ea99b56 fix(lua): copy_values and add tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 21:31:27 -08:00
Leonardo de Moura
c759fc93f7 test(lua): object Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 20:59:28 -08:00
Leonardo de Moura
351ef867d2 feat(lua): add abstract, instantiate, has_free_vars, lift/lower free_vars to Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 17:02:49 -08:00
Leonardo de Moura
ed3cf8152b feat(lua): add for_each to expr Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 16:30:59 -08:00
Leonardo de Moura
3dea7ae0d6 test(frontends/lean): example mixing Lean and Lua 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 16:07:15 -08:00
Leonardo de Moura
1bf6051866 test(lua): expr LUA API test 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 15:29:31 -08:00
Leonardo de Moura
9a22702383 feat(lua): make objects() and localobjects() methods return iterators in the environment LUA API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 14:26:01 -08:00
Leonardo de Moura
8c52d47692 chore(lua): rename env() to get_env() 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 13:58:51 -08:00
Leonardo de Moura
a80adae1c3 feat(lua): add fields method to sexpr Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 12:10:24 -08:00
Leonardo de Moura
450128e28b refactor(lua): cleanup Lua bindings, and add accessor/tester to expr Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-13 11:46:09 -08:00
Leonardo de Moura
be093ecf90 feat(lua): use formatter available in the state object to convert Lean objects into strings in the Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-12 16:56:30 -08:00
Leonardo de Moura
9a5f86fce6 feat(lua): use (** ... **) instead of {{ ... }} for nested Lua scripts 
The token }} is a bad delimiter for blocks of Lua script code nested in Lean files.
The problem is that the sequence }} occurs very often in Lua code because Lua uses { and } to build tables/lists/arrays.
Here is an example of Lua code that contains the sequence }}
     t = {{1, 2}, {2, 3}, {3, 4}}

In Lean, (* ... *) is used to create comments. Thus, (** ... **) code blocks will not affect
valid Lean files. It also looks reasonably good.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-12 16:05:49 -08:00
Leonardo de Moura
8190d4fed5 feat(lua): allow Lua scripts to update 'global' options 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-12 15:38:00 -08:00
Leonardo de Moura
b986af09ed feat(lua): add support for copying closures between Lua states 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-12 12:54:34 -08:00
Leonardo de Moura
2af2a69fc6 feat(lua): expose kernel objects in the Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-12 09:40:29 -08:00
Leonardo de Moura
d257156b88 fix(lua): memory leaks, we should not use luaL_error because it does not unwind C++ stack 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 21:45:13 -08:00
Leonardo de Moura
a30e02d862 fix(lua): redefine Lua 'print' function, and make sure it is thread safe 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 21:15:21 -08:00
Leonardo de Moura
eb9d0f0552 test(lua): add example showing how to access/update an environment object using multiple threads 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 20:53:23 -08:00
Leonardo de Moura
0af8f17834 feat(lua): allow Booleans to be copied between Lua states 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 20:39:46 -08:00
Leonardo de Moura
2ac594a159 test(lua): add a new example showing how to create nested State objects and threads 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 18:27:09 -08:00
Leonardo de Moura
69b41eae70 feat(lua): add support for multiple execution threads in the Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 16:25:17 -08:00
Leonardo de Moura
95785c7aaa feat(lua): add State objects, it allows us to create several Lua State objects in a lua script 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 15:05:50 -08:00
Leonardo de Moura
bdc23fba32 test(lua): add tests for expr object 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 13:11:31 -08:00
Leonardo de Moura
b227775a07 test(lua): add tests for format object 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 12:58:47 -08:00
Leonardo de Moura
c2db18a003 test(lua): add tests for sexpr object 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 09:51:07 -08:00
Leonardo de Moura
6c7be28807 test(lua): add tests for options object 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-11 09:42:50 -08:00
Leonardo de Moura
8c140ff86f feat(lua): allow lua scripts (embedded in Lean files) to access the environment 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-10 11:14:04 -08:00
Leonardo de Moura
3078923ea4 fix(kernel/type_checker): add missing test, and kernel_exception has_no_type_exception 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-10 11:14:04 -08:00
Leonardo de Moura
9d61fcf85b feat(lua): expose environment objects in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-10 11:14:04 -08:00
Leonardo de Moura
8dd62e76be feat(lua): add mk_metavar to Lua API 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-10 11:14:04 -08:00
Leonardo de Moura
554defe89d feat(lua): expose local_context objects in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-09 12:18:46 -08:00
Leonardo de Moura
ad2de3b53c feat(lua): expose level objects in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-08 17:08:24 -08:00
Leonardo de Moura
5a97f730af feat(lua): add Type function 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-08 15:52:58 -08:00
Leonardo de Moura
32605d8266 feat(lua): expose level objects in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-08 15:38:00 -08:00
Leonardo de Moura
cc17be1ef1 feat(lua): add is_* predicates 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-08 12:40:28 -08:00
Leonardo de Moura
5c35a9ad0a feat(lua): add Consts function 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-08 12:09:46 -08:00
Leonardo de Moura
b57ad80d5e feat(lua): expose basic API for Lean expressions in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-07 21:54:57 -08:00
Leonardo de Moura
9000c7c2fa feat(lua): expose format objects in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-07 21:54:42 -08:00
Leonardo de Moura
57b9657bf0 feat(lua): add lua_exception for wrapping lua errors, and improve Lua error messages in the Lean frontend 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-07 15:19:26 -08:00
Leonardo de Moura
a9b2be0b9c feat(frontends/lean): add support for embedded Lua scripts in Lean files 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-07 13:56:04 -08:00
Leonardo de Moura
9c60eed93c refactor(kernel/metavar): avoid using unique names for default metavariable prefix 
The problem is that unique names depend on the order compilation units are initialized. The order of initialization is not specified by the C++ standard. Then, different compilers (or even the same compiler) may produce different initialization orders, and consequently the metavariable prefix is going to be different for different builds. This is not a bug, but it makes unit tests to fail since the output produced by different builds is different for the same input file.
Avoiding unique name feature in the default metavariable prefix avoids this problem.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-07 10:16:25 -08:00
Leonardo de Moura
76150620c3 test(lua): use assertions 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-05 13:21:01 -08:00
Leonardo de Moura
ba3faea586 test(lua): add test driver for Lua binding tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-05 13:11:34 -08:00
Leonardo de Moura
0cc475e581 fix(lua/sexpr): make sexpr bindings robust 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-05 13:03:32 -08:00
Leonardo de Moura
56344c0541 test(lua): add more s-exprs Lua tests 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-04 21:31:29 -08:00
Leonardo de Moura
f13a97397f feat(lua): expose s-expressions in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-04 19:58:32 -08:00
Leonardo de Moura
3c475e890d refactor(lua/options): improve options bindings for Lua 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-04 18:46:58 -08:00
Leonardo de Moura
7b77863507 refactor(lua/name): improve name bindings for Lua 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-04 18:44:20 -08:00
Leonardo de Moura
9884c056ce feat(lua): allow Lean to be compiled with Lua 5.1 and LuaJit 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-03 12:40:44 -08:00
Leonardo de Moura
e2da8c1f4d feat(lua/numerics): expose mpz and mpq numbers in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-03 12:05:54 -08:00
Leonardo de Moura
dbf2d56c77 feat(lua/name): expose hierarchical names in the Lua bindings 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-02 20:49:42 -07:00
Leonardo de Moura
bf998d8661 feat(frontends/lean/parser): allow 'typeless' definitions, the type is inferred by the system 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-11-01 08:51:49 -07:00
Leonardo de Moura
96dcd003c6 fix(frontends/lean/parser): associated position with 'type' placeholder 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-10-31 16:27:36 -07:00
Leonardo de Moura
aa99ac6618 feat(kernel/value): allow semantic attachments to use coercions when being pretty printed 
For example, this feature is useful when displaying the integer value 10 with coercions enabled. In this case, we want to display "nat_to_int 10" instead of "10".

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-10-30 11:42:26 -07:00
Leonardo de Moura
032f5cd7b3 feat(frontends/lean): make the 'expression template' argument in Subst implicit because higher-order matching can infer it. 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-10-30 10:45:43 -07:00
Leonardo de Moura
bc92671ae4 fix(frontends/lean/notation): adjust the implicit arguments of TransExt, and add new test 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-10-29 17:12:50 -07:00
Leonardo de Moura
e3228b1f5c test(frontends/lean): add 'l = nil' test 
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
 2013-10-29 16:30:03 -07:00
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