Dramatic ultra-wide banner illustration, monochrome grayscale, dark matte charcoal background, subtle film grain. On the left, a single luminous geometric data token. It passes left to right in a straight horizontal beam through four distinct upright glass lenses arranged in a row, evenly spaced. Each lens refracts the same token differently: the first as a thin loose structural wireframe mesh; the second as a rigid affine lattice of parallel arrows; the third as a sealed engraved contract medallion with a precise rim; the fourth as a focused interrogation spotlight casting one sharp directional shadow. Technical schematic engraving aesthetic, fine etched linework, high contrast, cinematic rim light, clean negative space, no text, no letters, no words, no numbers.

Maps to the sections: structural (TypeScript) -> affine (Rust) -> refinement (Dafny) -> contracts and blame (Racket).

A deterministic magick schematic: a glowing token, a beam whose motif changes per segment (single line, double line, perpendicular ticks, dotted) as it passes four thin elliptical lenses, terminating in a filled spotlight cone. Grayscale, 8-bit, 728x90. Reproducible from /tmp/mkbanner.sh (committed prompt here; the script draws the four-segment beam + lenses + cone).