path: root/challenge-055/aecepoglu/bqn/ch-2.bqn

# 2
Perm←{𝕊0:0‿0⥊0; # permutation table with 𝕩 columns
      >⟨⟨0⟩⟩{n𝕊a:⥊(1+a){𝕨⌾(𝕩⊸/)n⥊0}⌜<˘¬=⌜˜↕n}´⌽1(⊣↓+)↕𝕩}
IsWave←∧´∘((≥‿≤⊏˜2|↕∘≠){𝕎´𝕩}¨⊢) 2(<˘↕)⊢
IsWave˘⊸/⊏⟜1‿2‿3‿4˘Perm 4