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
d0009d0242 feat(frontends/lean): make the first argument of if-expression implicit, add support for marking implicit arguments on builtin symbols (aka semantic attachments)
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-10-29 15:53:50 -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
e955c054ca Modify type checker. Now, it only accepts builtin values that have been declared in the environment. The idea is to be able to track which classes of builtin values have been used in a given environment. We want to be able to quantify the size of the trusted code base for a particular development.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-09-04 08:30:04 -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
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