which shows an unprobable burst of received errors such that each one of the decisions occurs at least once when the first cycle starts the entire information store 25 is filled with space symbols the space symbol is an a symbol denoted in fig2 by a it is assumed that the transmitter transmits a b symbol and continues to do so a faulty b symbol has the same parity as a and is denoted by b 39 on the basis of decision 1 ep 0 eb 0 and r g 34 0 34 in the second half of the cycle a b 39 erroneously received b with an even number of errors is written into the storage register 24 the new r g remains 34 0 34 because j r 0 k r x in the next cycle the buffer register 23 contains a correctly received b which is transferred to the storage register 24 in accordance with decision 2 the further cycles need no explanation b indicates when there is no transfer to the store the b already present in the relevant symbol address is not changed the displayed error b 39 in the first cycle can of course not be avoided in this example all following results are correct any other possible received sequence can be followed in a similar manner decision 2 with ep 34 1 34 and eb 34 0 34 seems to indicate a multiple and consequently very rare error as the information store 25 is initially filled with a 39 s and the probability that an a will be received is high this 34 error 34 will occur very frequently especially in the first cycle any double error occurring at a later instant will be treated.