Hello, everyone. Can I ask about MoreVP?

Nowadays I rarely see discussion about MoreVP

My question is very basic (and elementary):

How many (and what) challenge types are needed for STANDARD exit of MoreVP?

As far as I understand, I think the following 2 challenge types are needed.

M1. Spent output challenge

- Verify that an exiting UTXO isnāt already spent.

M2. Input double spend challenge

- Verify that all inputs to TX that contains an exiting UTXO arenāt spent by any other TXs.

- Verify that all inputs to TX that contains an exiting UTXO arenāt spent by any other standard exits.

- Verify that all inputs to TX that contains an exiting UTXO arenāt spent by any in-flight exits.

QUESTION: Are M1 and M2 necessary and sufficient for standard exit in MoreVP?

ā¦

In contrast to M1 and M2, the original version of Plasma Cash has the following 3 challenge types:

C1. Spent Coin Challenge

C2. Double Spend Challenge

C3. Invalid History Challenge

I think M1 and M2 correspond to C1 and C2 respectively.

Safety based on C3 in Cash is covered by exit-priority and in-flight exit system in MoreVP.

ADDITIONAL QUESTION: Is this understanding (correspondence between Cash <=> MoreVP) correct?