original: several versions of the protocol exist ; versions 1 3 occurred only internally at mit .
simplifications: many types of the protocol exist , the first three were only inside mit . several versions of the protocol exist ; versions 1 – 3 occurred only internally at mit . versions of the protocol exist with versions 1 and 3 interally at mit only . several kinds of the protocol exist : versions 1 3 occurred only internally at mit . all the versions of protocolexsising versions 1 3 occured internationally at mit many versions of the protocol exist ; versions 1 3 are only at mit . several versions of the protocol exist ; versions 1 3 occurred only internally at mit . several accounts of the approved design have existence ; accounts 1 3 occurred only on the inside at mit .