extend backward from def,0: anchor=#text("def")@0 focus=p#p2@0
extend backward again: anchor=#text("def")@0 focus=#text("abc")@3
extend forward from empty line: anchor=p#p2@0 focus=#text("def")@0
extend backward from empty line: anchor=p#p2@0 focus=#text("abc")@3
move forward from empty line: anchor=#text("def")@0 focus=#text("def")@0
move forward by line: anchor=p#p2@0 focus=p#p2@0
move to line start: anchor=#text("def")@0 focus=#text("def")@0
move to line end: anchor=#text("def")@3 focus=#text("def")@3
