• Input: data_x (implicit: timestamp_x)

• Set hash_x := sha3(CBOR(data_x, timestamp_x, typ, version))

• set I_n := list of x (that are not in I_{n-1})

• calculate itmh_n as merkle tree head of list(hash_x for x in I_n)

• for all x in I_n: set proof_x := calculate_proof(list(hash_x for x in I_n), x)

• set ith_n := {n, timestamp_n, itmh_n}

• commit new ith_n, calculate new mth_n

• announce mth_n, ith_n, consistency proof between mth_{n-1} and mth_n

    TIMESTAMP                                 INTERVAL

 ´-------------`                          ´´=============``
 |   data      |                          ||  interval   ||
´+-------------+`                         ||  timestamp  ||  SHA3  
||  timestamp  ||   SHA3                  ||  typ        +----------> ihash
||  typ        +------\                   ||  version    ||             |
||  version    ||     |              /--> ||  ith        ||             v
+`=============´+     |   *********  |    |`-------------`|          *********
|   hash        |  <--^-->* ITREE *--/    |   mth         | <------- * MTREE *
|   id          |         *********       |   proof       |          *********
|   proof       |                         `---------------´
+---------------+
.   tag         .
.................

hash: Hash of individual timestamp entry (contains data which is never stored anywhere)
tag: Stored in database but not returned in any API
ITREE (interval tree): Virtual merkle tree containing all hash of one interval. Not persisted anywhere.
ith (interval tree head): head of ITREE for one interval

ihash (interval hash): Hash of interval (contains ith)
MTREE (main tree): Main merkle tree, containing all ihash up to and including interval
mth (main tree head): head of MTREE at the time of interval

Compact external representation

mth: dev.unchanging.ink/$interval#v1:base64url($mth)
timestamp: dev.unchanging.ink/$interval#v1,$timestamp,base64url(cbor([$a,$path]))