Pattern matching

1. Value Just "Dawn" and pattern (Just variable)

   Yes: variable is bound to "Dawn". Extra parentheses don't affect the match.

2. Value Just "Dawn" and pattern Just "Brian"

   No: "Dawn" is different than "Brian".

3. Value Just "Dawn" and pattern Ok "Brian"

   No: both because "Dawn" is different than "Brian" and also because Just is different than OK.

4. Value Just "Dawn" and pattern Nothing

   No: something with two elements can't match something with one.

5. Value Just "Dawn" and pattern Ok variable

   No: Just is different than Ok

6. Value Just (Just "Dawn") and pattern Just (Just variable)

   Yes: Nested structures can be matched. variable is bound to "Dawn".

7. Value Just (Just "Dawn") and pattern Just variable

   Yes: and variable is bound to Just "Dawn". Variables can match substructures.