Using the taskbar
How to:
create a new petri-net
open an already existing file
save an existing file
save a file as
close current tub
print
add a place
add a transition
add a timed transition
add an annotation
add an arc
add a token
delete a token
select components
change grid size
toggle to animation mode
step backward a firing
step forward firing
randomly fire a transition
randomly fire a number of transitions