AR_i: the current accumulated rate at block i. AR_j / AR_i reflects the CKByte amount if one deposit 1 CKB to Nervos DAO at block i, and withdraw at block j.
S_i: the total unissued secondary issuance up to and including block i, including unclaimed Nervos DAO compensation and treasury funds.
U_i: the total occupied capacities currently in the blockchain up to and including block i. Occupied capacity is the sum of capacities used to store all cells.
C_i: the total issuance up to and including block i.