Formal Counterexamples with zoxiy

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Here is a video with sound which explains how to construct a possible situation both informally (by drawing it) and formally.

This video (with sound) explains how to construct a possible situation in which an identity statement is false, first informally and then formally.

Here you can see how to use zoxiy to create a possible situation in which a sentence involving quantifiers and predicates is true.

The trickiest task with possible situations is to construct a counterexample to an argument, as in this example.