Lewis Carroll's Game of Logic

In the preface to his Game of Logic Lewis Carroll remarked:

Besides nine counters, it also requires one Player, at least. I am not aware of any Game that can be played with less than this number: while there are several that require more.

In the applet below, the number of counters is limitless while, since you are reading this page, you have a chance to become a Player. The device is supposed to help you solve sorites problems. The applet consists of two parts: 12 trilateral diagrams and 3 diagrams. There is a check box at the bottom of the applet that pops up bilateral diagrams' window. That window is associated with a selected trilateral diagram. You may cycle through the latter by clicking "<" and ">" buttons. Trilateral diagrams have three attributes: horizontal, vertical, and inner denoted as x/x', y/y', and m/m'. In the bilateral diagram window you can give these attributes arbitrary names: type them in and press "Enter." The first bilateral diagram is used to define a statement with two attributes: x and m. The second should related y and m. For the applet to work, the two premises must be defined in such a way as to have eliminands twice as vertical attributes according to the diagram:

If you manage to do that, these two will serve as premises of a syllogism whose conclusion (if any) will by displayed in the third diagram.

The process is reflected in the trilateral diagrams. For example, this is how they look like for the sample sorites:

With the applet, it's easy to see that on the last step we might have drawn a stronger conclusion, viz., all b are c'. Please try other examples.

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Lewis Carroll's Game of Logic

What if applet does not run?

Lewis Carroll

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