The oldest algorithm you’ve never heard of
A zellige artisan in Fez doesn’t think in terms of “algorithms.” But when he selects tessellae, checks adjacency rules, applies symmetry constraints, and fills a plane without gaps — he’s executing a geometric program that’s been running for 700 years.
The vocabulary is different. The logic is identical.
What zellige IS (technically)
Zellige is a form of mosaic made from individually chiseled geometric tiles (tessellae) assembled into complex patterns. The patterns follow strict mathematical rules:
Symmetry groups. Every zellige pattern belongs to one of the 17 possible wallpaper groups (mathematical classification of plane symmetries). The artisans discovered these empirically — mathematicians proved them exhaustively only in the 19th century.
Adjacency constraints. Not every tile can be placed next to every other tile. There are rules about which shapes can neighbor which — a grammar of contact.
Tessellation. The tiles must fill the plane completely, with no gaps and no overlaps. This is a non-trivial constraint that limits which shapes are valid.
Color rules. Colors are not arbitrary. They follow alternation patterns, contrast rules, and symbolic conventions.
The computational parallel
| Zellige concept | Programming concept | |