Doubling calculator

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Possible doubles

 For all players  Set of own Wind. Set of Prevailing Wind. Set of Dragons.
Own Flower/Season. Set of Flowers/Seasons. Original call.
 For player going Mah-Jong No chows. All the same suit (and some honour).
All 1s/9s (one or more suits, some honour). All concealed.
Going Mah-Jong with a loose tile, the last available tile,
the final discard, original call or robbing the kong.

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