Mathematical/logic proof that unicorns exist.

Let's first define a set as a finite or infinite collection of unique objects. With sets you can also perform some operations on, like the union or intersection.

With that we define the existing set of all sets that do not contain themselves.

From that logically follows that unicorns exist.

This page is a permanent link to the reply below and its nested replies. See all post replies »

ArishMell · 70-79, M

And here was innocent I thinking "unicorn" refers to prairie monocultures....

I was introduced to basic Sets in a pilot maths syllabus at school, alongside the main and frankly far more useful "traditional" syllabus. Does anyone ever actually use Set Theory, with all its arcane caps and cups and Venn Diagrams (a 19C invention), for anything serious? Or is it just for illustrating middle-managers' 'Powerpoint' shows about profits on equine uniceratops?

Luke73 · 26-30, M

@ArishMell As soon as you start doing anything with math you need sets and set theory. Statistics, analysis, number theory, ... It's closely related to logic itself too.

ArishMell · 70-79, M

@Luke73 I'm used to seeing applied mathematics associated with science and engineering, and none of that used sets. It is mainly equations and formulae, a lot of them trigonometrical; series, calculus, logarithms; but I can see set theory would have applications in statistics.

Luke73 · 26-30, M

@ArishMell For example to define a function, you need to have sets. You need to have sets for all the basics.