4 lines
96 B
APL
4 lines
96 B
APL
|
|
upper ← ∘.!⍨¯1+⍳
|
|||
|
|
lower ← ⍉(∘.!⍨¯1+⍳)
|
|||
|
|
symmetric ← (⊢![1]∘.+⍨)¯1+⍳
|