305
Ok, at some point we made a big mistake.
(lemmy.world)
Hacker News post about this: https://news.ycombinator.com/item?id=39309783 (source available)
TL;DR:
Grid<A,B,C,D,E,F,G,H>simplifies to true, if and only if it is a 3x3 magic square.full explanation
Fifteenis an array of length 15T<A,B,C>checks if an array of lengthA+B+Cis equivalent to an array of length 15, thus checking ifA+B+Cis equal to 15And<A,X>is simplifies toXifAis true, else it simplifies tofalseDf<A,B,X>checks ifAandBare Diffrent , simplifying toXif they areGrid<A,B,C,D,E,F,G,H>first checks if every row, column and diagonal is equal to 15, then checks if every item is unique.