{HEAD ~ The interface} extends {TAIL ~ the remote procedure calling facility} beyond the distributed system by classifying the different types of remote procedure calls that can be issued to a switched communications gateway in the distributed system, and permitting the issuance of multiple threads of control, according to the type of function the procedure call represents 
extends
{ HEAD ~ The interface } extends { TAIL ~ the remote procedure calling facility } beyond the distributed system by classifying the different types of remote procedure calls that can be issued to a switched communications gateway in the distributed system , and permitting the issuance of multiple threads of control , according to the type of function the procedure call represents
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