ELI5: Explain Like I'm 5

Monadic predicate calculus

Okay kiddo, so imagine you have a basket of apples and you want to sort it out based on different qualities of the apples, like whether they are red, green or a mix of both, or whether they are big or small.

Now, to help you with this task, we have a special language called monadic predicate calculus, which allows you to describe these qualities using symbols and logical statements.

For example, you can use the symbol P(x) to mean "x is red" and the symbol Q(x) to mean "x is big". You can then use logical operators like "and" and "or" to link these statements together.

So, if you want to find all the big, red apples in your basket, you can write a statement like "for all x in the basket, if P(x) and Q(x) then x is a big, red apple".

This is the basic idea of monadic predicate calculus - using symbols and logical statements to describe properties of objects and how they relate to each other. It may sound complicated, but it's a really useful tool for solving problems in math, computer science and other fields.