Trying to lay out a Disappearing 9-Patch #quilt
Hallucinant ! As the French say.
I'm using a graphics program and my brain is still boggled. Such a simple function creates seemingly infinite repeating patterns. And if you add the possibility of both horizontal and vertical offsets to the offsets...
Our grandmamas may have been oppressed but it was not for lack of geometry and math skills, good lord. Anyone who could do this without a PC could run Ford or GM.