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Merge Rollup

The Merge rollup circuit is our in-between circuit, it doesn't need to perform any state updates, but mainly check the consistency of its inputs.

Overview​

Below is a subset of the data structures figure from earlier for easy reference.

Validity Conditions​

def MergeRollupCircuit(
    left: ChildRollupData,
    right: ChildRollupData
) -> BaseOrMergeRollupPublicInputs:
    assert left.proof.is_valid(left.public_inputs)
    assert right.proof.is_valid(right.public_inputs)

    assert left.public_inputs.constants == right.public_inputs.constants
    assert left.public_inputs.end == right.public_inputs.start
    assert left.public_inputs.num_txs >= right.public_inputs.num_txs
    assert left.public_inputs.end_sponge == right.public_inputs.start_sponge

    return BaseOrMergeRollupPublicInputs(
        type=1,
        num_txs=left.public_inputs.num_txs + right.public_inputs.num_txs,
        out_hash=SHA256(left.public_inputs.out_hash | right.public_inputs.out_hash),
        start=left.public_inputs.start,
        end=right.public_inputs.end,
        start_sponge=left.public_inputs.start_sponge,
        end_sponge=right.public_inputs.end_sponge,
        constants=left.public_inputs.constants
    )