{p,q} tessellation via geodesic reflections in H²
The Poincaré disk model of the hyperbolic plane H²: the open unit disk with metric ds² = 4(dx²+dy²)/(1−r²)². Geodesics are circular arcs orthogonal to the boundary. A {p,q} tiling (Schläfli symbol) requires 1/p + 1/q < 1/2 (hyperbolic condition). Tiles are generated by successive reflections across geodesic sides.