a$)$ Draw the Event$-$Driven Petri Net $($EDPN$)$ for Port events: P $=\{$p$1,$ p$2\}$ Data places: D $=\{$d$1,$ d$2,$ d$3\}$ Transitions: S $=\{$s$1,$ s$2,$ s$3,$ s$4\}$ In $=\{(($p$1,$ d$1),$ s$1),(($p$2,$ d$1),$ s$2),(($p$1,$ d$2),$ s$3),(($p$2,$ d$2),$ s$4)\}$ Out $=\{($s$1,$ s$2),($s$2,$ d$2),($s$3,$ d$3),($s$4,$ d$3)\}$