43 ;;Quote: normal Hypertext does not defining how nodes can be browsed, i.e., browsing semantics

43 ;;Quote: in Trellis, browsing semantics is based on petri nets

45 ;;Quote: a Trellis Hypertext is a petri net of links, user interface components, and mappings between them and the display

45 ;;Quote: map petri nets into hypertext by functions such as logical buttons for each transition

45_footnote ;;Quote: hide Hypertext elements by associating null elements with the petri net mappings

46 ;;Quote: a marking of a petri net defines the browsing state of a Trellis Hypertext; different initial markings give different browsing patterns

47 ;;Quote: a petri net can automatically synchronize multiple displays of Hypertext

48 ;;Quote: a petri net allows Hypertext browsing paths with non-adjacent common subsections

49 ;;Quote: if timing added to Hypertext petri nets, can implement timed exams and presentations

49 ;;Quote: a node of a Hypertext hierarchy can be a frame or another Hypertext