Struct ResolvedSibling 

pub struct ResolvedSibling<'a> {
    pub relative_index: i8,
    pub program_id: Pubkey,
    pub data: &'a [u8],
    pub accounts: &'a [Pubkey],
}

A top-level sibling instruction already read from the transaction, supplied to the hash so Op::IngestSiblingInstruction/Op::IngestSiblingAccount can fold its observed fields. On-chain the relay reads these from the instructions sysvar; off-chain the admin supplies the intended sibling when precomputing the authorized hash. Hashing stays a pure function of its inputs — it never touches the sysvar itself.

Fields

relative_index: i8

program_id: Pubkey

data: &'a [u8]

accounts: &'a [Pubkey]