Merged mining in JaxNetwork
Merge-mining of shard blocks
Nodes in JaxNet have a special agreement described in the protocol on how to perform merged mining. Every miner composes a Merkle tree in which he places his shard block candidates. In JaxNet protocol this data structure is called Merge-mining Merkle Tree (MMMT) since it is used for merge-mining. Another name for it is Shard Merkle Tree (SMT) since its leaves correspond to shards in JaxNetwork.
Shard Merkle Tree
The set of shards in JaxNet are in one-to-one correspondence with the set of leaves of Shard Merkle Tree: the first leaf from the left corresponds to the first shard, the second leaf to the second shard and so on. It is allowed to merge-mine the shard block only on the leaves of the Shard Merkle Tree which corresponds to this shard. Blocks which are merge-mined in the wrong place should be rejected during the block verification within the shard.