E.g., if the user uses the expression “x * x” in a spreadsheet cell and wires an equality constraint to the value of that cell that forces it to be 9, the system will run the computation backwards and make the input to that spreadsheet cell be 3. @Marcel Goethals provided a more interesting example, where the system would recognize a certain configuration of objects as a slider, and associate whatever additional state to those objects in order to make the slider behavior work. The slider field (shown in the video above) associates several objects with the point that becomes the “thumb” of the slider: