2017-10-10 11:09 GMT-03:00 Tao Effect via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org>:
When you transfer them back, you get newly minted coins, equivalent to the amount you "burned" on the chain you're transferring from — as stated in the OP.

If you have to change Bitcoin to recognize a transfer from the sidechain back into Bitcoin, you kill the purpose of the sidechain. You could as well just change the Bitcoin to implement whatever desirable features the sidechain would have. The whole idea of sidechains is to keep Bicoin unchangend, and allow for the voluntary transfer of tokens out of Bitcoin to the sidechain of your choosing.


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Lucas Clemente Vella
lvella@gmail.com