s the button Redo: All. The Simulator replays the scenario, reaches the stop condition, and displays: stop condition: (dlca!dlc(1) state = connected) and (dlcb!dlc (1) ! state = connected) 15 transitions executed end of scenario execution The Editor displays the MSC trace corresponding to the stop condition scenario. D. Enter the command print state; the Simulator answers: > print state btoa (1) ! state = ready atob (1) ! state = ready dlcb!dlc (1) ! state = connected dlca!dlc (1) ! state = connected We see that the two instances of process DLC are in state connected. Apart from proving properties, stop conditions are very handy for quickly finding a situation in an SDL model. 7.4.10 Exhaustive simulation with MSC observers More details on MSC observers are provided in Chapter 5. You will simulate the V.76 SDL model observed by the MSC testl.msc. If necessary, several MSCs can observe the SDL model, together with stop conditions and GOAL observers. 252 Validation of Communications Systems with SDL 7.4.10.1 Compile the SDL model plus the MSC A. With a text editor, open the file v76.startup and insert a comment delimiter - - as below in front of the feed source line (because here we use the feeds generated by the MSC): source v76_feed.wri B. In the SDL (and MSC) Editor, load the V.76 SDL model plus the MSC testl.msc. C. In the SDL Editor, select the file testl.msc and do Edit > MSC Simulation Properties: select verify and press OK. The Simulator will find more rapidly a scenario complying with the MSC. Using search, the simulation would take more time (especially with Reasonable environment off). D. Save the MSC. E. Unload any other files from the SDL Editor, and quit (do NOT minimize) the ObjectGeode Launcher if running. F. In the SDL Editor, select Tools > SDL & MSC Simulator. G. In the ObjectGeode Launcher, check that the left area only contains v76.pr and testl.msc. H. Press the Build button. 7.4.10.2 Run the exhaustive simulation A. Press the Execute button to start the Simulator. The Simulator main window app