anchor.diff:     
      Stmt handleRead =
      seq
  +      while(True)
  +   seq
         if (read_item.notEmpty())
   	 seq
   	    rf.read.address(zeroExtend(read_item.first().address));
  
positive.code:    method Action read_rf(Bit#(16) address, Bit#(16) data);
        if (verbose) $display("mkMain::read_rf");
        read_item.enq(RFItem{address:truncate(address), data:0});
        readFSM.start();
     endmethod
  
     endinterface
  endmodule
  
negative.code: 	       indication.read_rf(zeroExtend(read_item.first().address), zeroExtend(rf.read.data()));
  	    endaction
  	 endseq
        endseq
     endseq;
     
    mkAutoFSM(handleRead);
     
     interface MainRequest request;
  
  