List of Figures

• A portal is a camera/monitor pair. Objects visible below the camera appear on the surface of the monitor, scaled to fit. Furthermore, events which hit the surface of the monitor are transmitted to the objects below the camera.
• A text editing filter is placed over two text objects.
• Semantic Zooming in Cartography
• Composed filters can create multiple filtered objects.
• The root of the tablet inheritance graph.
• An event passes through filters f₃, f₂ and f₁ and hits an object. Then the filter stack is searched for that object's topmost delegator, d₂, which is found in f₂.
• Initial system configuration.
• A magnifier is a framed portal whose camera is constrained to stay directly below the frame. When the camera is smaller than the portal (as shown here) it is enlarging.

2.02.0