TIL prefix notation (aka Polish notation) was invented in 1924 by Jan Łukasiewic, who apparently just dropped it in an article not about the notation at all. Which is a pretty ballsy thing. (Actual quote: “I came upon the idea of a parenthesis-free notation in 1924. I used that notation for the first time in my article Łukasiewic(1)”) That also seems par for the course for mathematicians.

Seriously. Łukasiewic’s didn’t just shift the existing symbols to the front, he replaced them all with letters. Now granted, they’re the first letter of the Polish word for the operation, but he wasn’t done! For you see, operations that were already fancy letters, like ∀ and ∃, he replaced them with Greek letters that don’t correspond to anything!

“N stands for negation.”

“Of course!”

“A will be used for disjunction, or as we call it Poland, ‘alternatywa’.”

“Makes sense!”

“And the tee operator will be replaced with V, because in Latin, ‘true’ is called ‘vernum’.”

“Interesting, but I get it.”

“And the inverted tee will be replaced with O!”

“Is that because ‘false’ starts with an ‘o’ in Polish?”

“No. no. It is cognate. It’s ‘fałsz’, ‘false’, ‘falsum’. It’s all the same. No. It is ‘O’, because it is the opposite of true.”

“Oh… Okay.”

“And the the existential qualifier, will no longer be that hideous backwards it. It will be a capital sigma, for ‘kwantyfikator szczegółowy’!”

“But you haven’t used ‘S’.”

“Sigma is like S, but better.”

“I guess.”

“And now the turned a will become a capital pi!”

“Because ‘universal’ starts with a ‘p’ in Polish?”

And this my friends is how I learned that “conjunction” is called “koniukcja” is Polish, and “disjunction” in Polish is called “alternatywa”, and “nonconjunction” is called “dysjunkcja”.

Oh but it gets better! For some things like like possibility (typically denoted with a ◊), he used an M for “możliwość”, but then he swapped it out for a delta, and then he went back to an M.

Then for necessity, he replaced the square with a capital gamma, because he already used a K for koniunkcja, and so he couldn’t use it for konieczność, and K and G sound similar right?

But then when was purging the Greek letters, he went with an L, because it’s an upside down gamma.🤯

But my favorite letter is replacing the E for ekwiwalencja (biconditional) with… a Q!