.Theorem {counter:theorem:A}
3 is odd.        

.Theorem {counter:theorem}
4 is even.

{counter:new} {counter:new}
 
{counter:new:15} should be 3.

{counter:special:4} should be 4.
and now {counter:special}
>>>
Document
  { docMeta =
      Meta
        { docTitle = []
        , docTitleAttributes = Nothing
        , docAuthors = []
        , docRevision = Nothing
        , docAttributes = fromList [ ( "sectids" , "" ) ]
        }
  , docBlocks =
      [ Block
          mempty
          (Just
             (BlockTitle
                [ Inline mempty (Str "Theorem ")
                , Inline mempty (Counter "theorem" UpperAlphaCounter 1)
                ]))
          (Paragraph [ Inline mempty (Str "3 is odd.") ])
      , Block
          mempty
          (Just
             (BlockTitle
                [ Inline mempty (Str "Theorem ")
                , Inline mempty (Counter "theorem" UpperAlphaCounter 2)
                ]))
          (Paragraph [ Inline mempty (Str "4 is even.") ])
      , Block
          mempty
          Nothing
          (Paragraph
             [ Inline mempty (Counter "new" DecimalCounter 1)
             , Inline mempty (Str " ")
             , Inline mempty (Counter "new" DecimalCounter 2)
             ])
      , Block
          mempty
          Nothing
          (Paragraph
             [ Inline mempty (Counter "new" DecimalCounter 3)
             , Inline mempty (Str " should be 3.")
             ])
      , Block
          mempty
          Nothing
          (Paragraph
             [ Inline mempty (Counter "special" DecimalCounter 4)
             , Inline mempty (Str " should be 4.\nand now ")
             , Inline mempty (Counter "special" DecimalCounter 5)
             ])
      ]
  }