Function is_proof_of_time_valid 

pub fn is_proof_of_time_valid(
    parent_hash: <PassPointerAndReadCopy<BlockHash, 32> as RIType>::Inner,
    slot: <SlotNumber as RIType>::Inner,
    proof_of_time: <PassFatPointerAndDecode<WrappedPotOutput> as RIType>::Inner,
    quick_verification: <bool as RIType>::Inner,
) -> <bool as RIType>::Inner

Verify whether proof_of_time is valid at specified slot if built on top of parent_hash fork of the chain.