Listing 2. Pseudocode for approving the document version.

// Define the structure for a participant struct Participant {    bool registered;    bool approved; } // Contract state enum ContractState {   Created,   WaitForApproversSignature,   Reverted } # Define contract states class ContractState:   Created = "Created"   WaitForApproversSignature = "WaitForApproversSignature" # Define participant states class ParticipantState:   ReadyToSubmit = "ReadyToSubmit"   SubmittedForApproval = "SubmittedForApproval" # List of registered participants RegisteredParticipants = [] def validateParticipant(participantAddress, IPFSHash):    contractState = ContractState.Created    participantState = ParticipantState.ReadyToSubmit    if participantAddress in RegisteredParticipants:         restrictAccessToParticipant(participantAddress)         if IPFSHash:             contractState = ContractState.WaitForApproversSignature             participantState = ParticipantState.SubmittedForApproval             createValidationMessage("Requesting validation from all approvers")         else:             revertContractState("IPFS hash is not provided")    else:         revertContractState("Participant is not registered") def restrictAccessToParticipant(participantAddress):    # Restrict access to only the specified participant    pass def createValidationMessage(message):    # Create a validation message with the given content    pass def revertContractState(error):    # Revert contract state and show error message    pass