src/HOL/TLA/Memory/RPCParameters.thy

A formalization of TLA in HOL -- by Stephan Merz;

(*
    File:        RPCParameters.thy
    Author:      Stephan Merz
    Copyright:   1997 University of Munich

    Theory Name: RPCParameters
    Logic Image: TLA

    RPC-Memory example: RPC parameters
    For simplicity, specify the instance of RPC that is used in the
    memory implementation.
*)

RPCParameters = MemoryParameters +

datatype  rpcOps = remoteCall
datatype  rpcState = rpcA | rpcB

types
  (* type of RPC arguments other than memory calls *)
  noMemArgType
  (* legal arguments for (our instance of) the RPC component *)
  rpcArgType = "(rpcOps * memArgType) + (rpcOps * noMemArgType)"

arities
  noMemArgType :: term

consts
  (* some particular return values *)
  RPCFailure     :: "Vals"
  BadCall        :: "Vals"
  
  (* Translate an rpc call to a memory call and test if the current argument
     is legal for the receiver (i.e., the memory). This can now be a little
     simpler than for the generic RPC component. RelayArg returns an arbitrary
     memory call for illegal arguments. *)
  IsLegalRcvArg  :: "rpcArgType => bool"
  RPCRelayArg    :: "rpcArgType => memArgType"

rules
  (* RPCFailure is different from MemVals and exceptions *)
  RFNoMemVal        "~(MemVal RPCFailure)"
  NotAResultNotRF   "NotAResult ~= RPCFailure"
  OKNotRF           "OK ~= RPCFailure"
  BANotRF           "BadArg ~= RPCFailure"

  IsLegalRcvArg_def "IsLegalRcvArg ra == EX marg. ra = Inl (remoteCall,marg)"
  RPCRelayArg_def   "RPCRelayArg ra == 
                         case ra of Inl (rm) => (snd rm)
                                  | Inr (rn) => Inl (read, @ l. True)"

end