效绵县 State ■ The state of the system is modeled by marking the places with tokens A place can be marked with a finite number (possibly zero)of tokens
State ◼ The state of the system is modeled by marking the places with tokens ◼ A place can be marked with a finite number (possibly zero) of tokens
效绵鼎 Fire A transition t is called enabled in a certain marking,if: For every arc from a place p to t,there exists a distinct token in the marking ■ An enabled transition can fire and result in a new marking Firing of a transition t in a marking is an atomic operation state transition of form (1,0)>(0,1) p:input place p2:output place 十 P2
Fire ◼ A transition t is called enabled in a certain marking, if: For every arc from a place p to t, there exists a distinct token in the marking ◼ An enabled transition can fire and result in a new marking ◼ Firing of a transition t in a marking is an atomic operation state transition of form (1, 0) → (0, 1) p1 : input place p2 : output place p1 p2 t1
绵鼎 Fire (cont.) Firing a transition results in two things: 1. Subtracting one token from the marking of any place p for every arc connecting p to t 2. Adding one token to the marking of any place p for every arc connecting t to p ●
Fire (cont.) ◼ Firing a transition results in two things: 1. Subtracting one token from the marking of any place p for every arc connecting p to t 2. Adding one token to the marking of any place p for every arc connecting t to p
效绵鼎 Firing example 2H2+02→2H20 。 2 H2 2 H2O 02
Firing example 2H2 + O2 → 2H2O H2 O2 H2O t 2 2
效绵鼎 Firing example 2H2+02→2H20 2 H2 2 H2O 02
Firing example 2H2 + O2 → 2H2O H2 O2 H2O t 2 2