module OK (TYPES, CHANNELS) is

process MAIN [RECEIVE_BLOCK_PROPOSAL: BLOCK, COMMIT_PROPOSED_BLOCK: COMMIT,
              COMMIT_EMPTY_BLOCK: COMMIT] is
   loop
      RECEIVE_BLOCK_PROPOSAL (?any BIT);
      alt
         i;
         COMMIT_PROPOSED_BLOCK
      []
         i;
         COMMIT_EMPTY_BLOCK
      end alt
   end loop
end process

end module