A simple interactive truth table for proving the invalidity of the two different fallacious forms of argumentation that look a lot <em>like</em> Disjunctive Syllogism.

Click ‘start’ to begin. Then click on the ‘P’ and ‘Q’ on the left to drag the truth-values to the atomic components of the sentences. You’ll see a T/F appear under each connective. Set the correct values and click on ‘Check’ to verify. When the table is completed, it will prompt you to highlight any rows with a false conclusion, and then circle the truth-values of the premises to verify if they are both true. If there are no rows with true premises and a false conclusion, it’s valid (by definition).

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