↕)↕ 𝕩: RangeReturn all indices to index into an array of shape 𝕩, in the shape described by 𝕩.
When given a single number, range from 0 to 𝕩-1.
↕ 4 ⟨ 0 1 2 3 ⟩ ↕ 4‿5 ┌─ ╵ ⟨ 0 0 ⟩ ⟨ 0 1 ⟩ ⟨ 0 2 ⟩ ⟨ 0 3 ⟩ ⟨ 0 4 ⟩ ⟨ 1 0 ⟩ ⟨ 1 1 ⟩ ⟨ 1 2 ⟩ ⟨ 1 3 ⟩ ⟨ 1 4 ⟩ ⟨ 2 0 ⟩ ⟨ 2 1 ⟩ ⟨ 2 2 ⟩ ⟨ 2 3 ⟩ ⟨ 2 4 ⟩ ⟨ 3 0 ⟩ ⟨ 3 1 ⟩ ⟨ 3 2 ⟩ ⟨ 3 3 ⟩ ⟨ 3 4 ⟩ ┘
𝕨 ↕ 𝕩: WindowsOverlapping slices of 𝕩 which are of shape 𝕨.
5 ↕ "abcdefg" ┌─ ╵"abcde bcdef cdefg" ┘ a ← 3‿3⥊↕9 2‿2 ↕ a ┌─ ┆ 0 1 3 4 1 2 4 5 3 4 6 7 4 5 7 8 ┘