chore(kernel/replace_fn): add syntax sugar for replace function

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(library/choice): we should be able to store 'choice' operators in .olean files, this can happen because of notation decls

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(kernel/constraint): add 'print' function for debugging purposes

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/standard): add equivalence inductive predicate

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(library/module): module index assignment

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(kernel/error_msgs): move pp_type_mismatch to error_msgs module

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/unifier): improve error message when metavar assignment is type incorrect

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/standard/bit): add theorems and notation

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/standard): add decidable class

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/standard): add more decidable instances

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
chore(frontends/lean): add 'replace' auxiliary funcs

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(library/choice): style

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(library/choice): style