Round
The round or round number is a 64-bit unsigned integer that indexes into the sequence of states and blocks.
The round \( r \) of each block is one greater than the round of the previous block (\( r_i = r_{i-1} + 1 \)).
Given a Ledger \( L \), the round of a block exclusively identifies it.
The rest of this document describes components of states and blocks with respect to some implicit Ledger. Thus, the round exclusively describes some component, and we denote the round of a component with a subscript. For instance, the timestamp of state/block \( r \) is denoted \( t_r \).