Predicate Logic and Popular Culture (Part 43): Prince

Let be the proposition “You are rich,” let be the proposition “You are my girl,” let be the proposition “You are cool,” and let be the proposition “You rule my world.” Translate the logical statement

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The straightforward way of translating this into English is, “It is false that if you’re my girl, then you’re rich, and it’s false that if you rule my world, then you’re cool.” This is the chorus of one of Prince’s biggest hits. Unfortunately, I can’t find a good version of Prince’s song on YouTube, so here’s a cover by Tom Jones instead.

More recently, this song was covered near the start of the animated movie Happy Feet.

Context: This semester, I taught discrete mathematics for the first time. Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.

In an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.

When I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.