MODULEHello EXPORTSMain ; IMPORT Trestle, TextVBT; VAR (* construct a VBT to be installed as the top level window *) main := TextVBT.New("Hello World"); BEGIN (* Install it as a top level window *) Trestle.Install(main); (* Wait until the installed VBT is deleted *) Trestle.AwaitDelete(main) END Hello.