A process always has one start event and at least one end event :
A process can have several end events but cannot have several start events:
A start event always has a unique output stream. An end event always has a unique input stream :
Antask always has a unique input flow AND a unique output flow :
gate is either opening or closing:=””>
The doors work in pairs:
The opening and closing logic doors (which work together) are of the same type:
When two tasks are similar “to within a certain amount”, it is the same task: