fFc=: (32&+)@(*&1.8) ]b=:fFc _40 0 100 _40 32 212 cFf=: fFc^:_1 cFf b _40 0 100片語 f &. g 的結果為動詞 (g^:_1)@(f & g)。函數 g 可視為為了"主" 函數 f 的應用做準備 (之前執行，之後反向執行) 。例如：
b=: 0 0 1 0 1 0 1 1 0 0 0
sup=: </\ 刪除除了首項外之所有 1
sup b
0 0 1 0 0 0 0 0 0 0 0
|. sup |. b 刪除除了末項外之所有 1
0 0 0 0 0 0 0 1 0 0 0
sup&.|. b
0 0 0 0 0 0 0 1 0 0 0
3 +&.^. 4 取對數、相加、再取逆對數
12
(^.3)+(^.4)
2.48491
^ (^.3)+(^.4)
12
]c=: 1 2 3;4 5;6 7 8
+-----+---+-----+
|1 2 3|4 5|6 7 8|
+-----+---+-----+
|.&.> c 開啟，反向與封箱
+-----+---+-----+
|3 2 1|5 4|8 7 6|
+-----+---+-----+
練習
| 27.1 | Use following as exercises in reading與writing.
Try using引數such as a=: 2 3 5 7 and b=: 1 2 3 4
and c=: <@i."0 i. 3 4 : f=: +&.^ Multiplication by addition of natural logs g=: +&.(10&^.) Multiplication using base-10 logs h=: *&.^ Addition from multiplication i=: |.&.> Reverse each box j=: +/&.> Sum each box k=: +/&> Sum each box與leave開啟 |