Click points to add or remove them. No three selected points may sum to (0, 0) mod 3.
size: 0 / max 4
The 9 grid points are F32 = {0,1,2}². A "line" is any three points x, y, z with x + y + z ≡ (0,0) mod 3 — this includes rows, columns, both diagonals, and "wrap-around" triples like (0,0)+(1,2)+(2,1). The maximum cap set in F32 has size 4.