Commit graph

8 commits

Author SHA1 Message Date
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
Leonardo de Moura
2ca30571b4 Display the input term in the output of the Check command. It is useful to see the fully elaborated term.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-08 22:55:21 -07:00
Leonardo de Moura
df116f88e0 Improve pretty printer for Pi's
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-08 11:04:07 -07:00
Leonardo de Moura
a341643335 Fix unit tests for Windows
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-03 10:44:51 -07:00
Leonardo de Moura
e218b92a9d Modify verbose message for Set command
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-02 12:29:21 -07:00
Leonardo de Moura
0a67679afb Add natural numbers. Fix how coercions and overloads interact (switch to approach used in C++). Add notation for natural and integer arithmetic. Rename m and u universe variables to M and U.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-02 12:24:29 -07:00
Leonardo de Moura
a3bbd9fbb5 Minimize use the colors in tests. The colors make the diff hard to read
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-01 10:34:57 -07:00
Leonardo de Moura
51640ecff8 Move files in examples directory to tests directory. They are not real examples
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-08-31 19:16:30 -07:00