_fix ← { 𝕩 ≡ 𝕨 𝔽 𝕩 ? 𝕩 ; 𝕨 𝕊 𝕨 𝔽 𝕩 }
d←>'0'-˜•FLines"day15"

Lens ← {q←(⊑⌽≢𝕩)⥊∞ ⋄ 𝕩 {𝕩⌊𝕨+(q»𝕩)⌊(q«𝕩)⌊(∞»˘𝕩)⌊(∞«˘𝕩)}_fix 0⌾⊑ ∞⌈𝕩}

•Show ⊑⌽˘⌽ Lens d                       # 626
•Show ⊑⌽˘⌽ Lens 9⊸|⌾(-⟜1)+∾(<d)++⌜˜↕5  # 2966