Scyther related questions for handling/splitting values and verifying hashes

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While implementing a protocol in Scyther, I need help with the following questions -

  1. How do we split a particular message/variable into two parts in Scyther? (For eg. if I have value R in my protocol that I need to divide into two parts say K1 and K2, how do I go about doing it in Scyther. I tried R=CONCAT(K1, K2) where all R, K1 and K2 are of the same type but I don't know whether it is the correct way)
  2. How do we verify the hashes received by both entities? (For eg. There is a message M that is generated by the sender S and he/she sends M and Hash(M) to the receiver R. A copy of the message, M' is already stored at the receiver R, then if we want to verify the values Hash(M) with Hash(M'), how do we do that? I tried using match() function but it shows some error)
  3. How do we handle the values that are claimed to be stored in the database of the entities? (For eg. a sender registers itself with the receiver by sending his unique ID and the receiver stores the ID received in its database for future reference, how do we depict this scenario in Scyther?)

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