🦞🌯 Lobster Roll

a few weeks ago, i gained a need for something roughly spreadsheet-shaped. very tiny—1e4 or 1e5 rows, if that. i decided my options were: - literal spreadsheet - sqlite plus some sugar - mathematica notebook i have never used mathematica before in any serious capacity (nor anything else in...

> We prove that the following problem is co-RE-complete and thus undecidable: given three simple polygons, is there a tiling of the plane where every tile is an isometry of one of the three polygons (either allowing or forbidding reflections)? This result improves on the best previous construction w...