# File RPC.ML

    (*
        File:        RPC.ML
        ID:          $Id: RPC.ML,v 1.6 2005/09/07 18:22:43 wenzelm Exp $
        Author:      Stephan Merz
        Copyright:   1997 University of Munich

        RPC-Memory example: RPC specification (theorems and proofs)
    *)

    val RPC_action_defs = [RPCInit_def, RPCFwd_def, RPCReject_def, RPCFail_def,
                           RPCReply_def, RPCNext_def];

    val RPC_temp_defs = [RPCIPSpec_def, RPCISpec_def];

    val mem_css = (claset(), simpset());

    (* The RPC component engages in an action for process p only if there is an outstanding,
       unanswered call for that process.
    *)

    Goal "|- ~$(Calling send p) --> ~RPCNext send rcv rst p";
    by (auto_tac (mem_css addsimps2 (Return_def::RPC_action_defs)));
    qed "RPCidle";

    Goal "|- $(Calling rcv p) & $(rst!p) = #rpcB --> ~RPCNext send rcv rst p";
    by (auto_tac (mem_css addsimps2 RPC_action_defs));
    qed "RPCbusy";

    (* RPC failure actions are visible. *)
    Goal "|- RPCFail send rcv rst p --> \
    \        <RPCNext send rcv rst p>_(rst!p, rtrner send!p, caller rcv!p)";
    by (auto_tac (claset() addSDs [Return_changed],
                 simpset() addsimps [angle_def,RPCNext_def,RPCFail_def]));
    qed "RPCFail_vis";

    Goal "|- Enabled (RPCFail send rcv rst p) --> \
    \        Enabled (<RPCNext send rcv rst p>_(rst!p, rtrner send!p, caller rcv!p))";
    by (force_tac (mem_css addSEs2 [enabled_mono,RPCFail_vis]) 1);
    qed "RPCFail_Next_enabled";

    (* Enabledness of some actions *)
    Goal "!!p. basevars (rtrner send!p, caller rcv!p, rst!p) ==> \
    \     |- ~Calling rcv p & Calling send p --> Enabled (RPCFail send rcv rst p)";
    by (action_simp_tac (simpset() addsimps [RPCFail_def,Return_def,caller_def,rtrner_def])
                        [exI] [base_enabled,Pair_inject] 1);
    qed "RPCFail_enabled";

    Goal "!!p. basevars (rtrner send!p, caller rcv!p, rst!p) ==> \
    \     |- ~Calling rcv p & Calling send p & rst!p = #rpcB \
    \        --> Enabled (RPCReply send rcv rst p)";
    by (action_simp_tac (simpset() addsimps [RPCReply_def,Return_def,caller_def,rtrner_def])
                        [exI] [base_enabled,Pair_inject] 1);
    qed "RPCReply_enabled";