(b) Embedded software is to be developed for a digital video recorder (DVR). People use the DVR to record TV programmeseither what they are watching right now or programmes to be shown in the future. Users can browse the electronic programme guide (EPG) to find programme information (channel, time, description) in various ways and to set up recordings. The DVR downloads EPG data updates at regular intervals (e.g. hourly). Access to EPG data is via the internet and requires an EPG service subscription. The user may set up recording for an entire series without having to separately set up each recording. Furthermore, the user can record while watching a recorded programme or start watching a programme that is still being recorded. A user can choose where in the programme to start watching (the default is from last viewed point or the start of programme). Finally, because storage is limited users control how and when to delete recordings. (i) Write the actor-goal list for the application including a brief (one line) description of each actor. (ii) For all use cases in the system (about 3) write the detailed form of the main scenario (usually just 2-4 steps) and a very brief form of all the extension scenarios you can identify. (iii) Draw a use case diagram to summarize the system. (b) Embedded software is to be developed for a digital video recorder (DVR). People use the DVR to record TV programmeseither what they are watching right now or programmes to be shown in the future. Users can browse the electronic programme guide (EPG) to find programme information (channel, time, description) in various ways and to set up recordings. The DVR downloads EPG data updates at regular intervals (e.g. hourly). Access to EPG data is via the internet and requires an EPG service subscription. The user may set up recording for an entire series without having to separately set up each recording. Furthermore, the user can record while watching a recorded programme or start watching a programme that is still being recorded. A user can choose where in the programme to start watching (the default is from last viewed point or the start of programme). Finally, because storage is limited users control how and when to delete recordings. (i) Write the actor-goal list for the application including a brief (one line) description of each actor. (ii) For all use cases in the system (about 3) write the detailed form of the main scenario (usually just 2-4 steps) and a very brief form of all the extension scenarios you can identify. (iii) Draw a use case diagram to summarize the system