(⊂+/a×(⍴a)⍴1 2○⊃x)⍪⍨⊂-/a×(⍴a)⍴2 1○⊃x
12○⊣+0J1×⊢
⎕
{…}1
⍴
↑…⊆
×⍤1
⍵○⊃x
1 10
a
4 2⍴⍳8
×
(×⍤1)
×⍤1⊢
(⊃x)0∘+⍢polar⊢⍬2⍴1↓x
(⊃x)
pol
(⊣,',',⊢)/⍕¨
x←⎕
⍉
,¨
⍪
⍭⊢a←