Add implicit argument management to lean frontend.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Add implicit argument declarations to lean parser.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Improve lean pretty printer support for implicit argument annotations

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Add basic support for hiding implicit arguments when pretty printing.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Implement support for notation + implicit arguments. Cleanup pretty printer code for handling implicit arguments.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Rename get_exs in oper to get_deno

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Add missing mixfix notation

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Uniform notation declarations.
Remove obsolete commands.
Simplify the elaborator

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>