[Bug-apl] Quite strange bug

[Christian Robert]

      )load Grid
SAVED 2016-11-06 22:51:16 (GMT-5)

      )fns
Randomize   df  gengrid     permute
      )vars

      gengrid
3 4 7
2 8 5
6 1 9
      )vars
G
      )erase G

      gengrid
9 8 2
3 7 6
5 1 4
      )vars
      ⍝ where is G ?

      )vars
      ⎕nc 'G'
0
      ⍴G
362880 3 3
      )vars
G
      ⎕nc 'G'
2

Xtian.

Gere the content of Grid in .apl format

#!/usr/local/bin/apl --script
 ⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝
⍝
⍝ x 2016-11-06 23:00:56 (GMT-5)
⍝
 ⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝⍝

∇Randomize ;fd
 fd ← ⎕fio[3] '/dev/urandom'
 ⎕rl←(7⍴256)⊥7 ⎕fio[41] fd
 ⊣ ⎕fio[4] fd
∇

∇df;names;func;lambda;⎕pw;t
 ⎕pw←10000
 names←((⊂[⎕io+1]⎕nl 3 4)~¨' ')~ ⊂"df"
 lambda←({'λ'=↑⎕cr ⍵}¨names)/names
 →(2> ⍴lambda)/nosrtl
 lambda←{⍵[⎕av⍋⊃⍵]} lambda
 nosrtl: func←names~lambda
 →(2>⍴func)/nosrtf
 func←{⍵[⎕av⍋⊃⍵]} func
 nosrtf: func←{⍵ (22 ⎕cr ⎕cr ⍵)} ¨ func
 lambda←{⍵,'←{',({⌽ {(+/^\' '=⍵)↓⍵} ⌽ ⍵} 2↓((⎕cr ⍵)[1+⎕io;])),({{⌽ {(+/^\' 
'=⍵)↓⍵} ⌽ ⍵} {(∨\t=';')/t←(⎕cr ⍵)[⎕io;]} ⍵} ⍵),'}'} ¨ lambda
 ⎕←,[⍳0] {((⍴,⍵)⌊(¯2+⎕fio ¯8))↑,⍵} ¨ ⊂[⎕io+1]⍕ ,[⍳0] ,func,(⊂' '),lambda,(⊂' ')
∇

∇z←gengrid ;P;Idx;cube;randcube;⎕IO
 ⎕IO←1
 cube←{((↑⍴⍵),⍺)⍴,⍵}
 randcube←{⍵[(↑⍴⍵)?↑⍴⍵;;]}
 →((2=⎕nc 'G'))/Ok
  Randomize
  G ← randcube 3 3 cube permute ⍳9
 Ok: P ← 9⍴0
 P[1] ← 1
 z ← G[P[1];;]
∇

∇z←permute s
 →((⍴,s)≤1)/ident
 →((⍴s)>2)/recurse
 z←s⍪1 2⍴⌽s ⋄ →0
 ident: z←s ⋄ →0
 recurse: z←(((⍴,z)÷⍴s),⍴s)⍴,z←{⍵,permute s~⍵}⍤0 s
∇

⎕CT←1E¯13

⎕FC←(,⎕UCS 46 44 8902 48 95 175)

⎕IO←1

⎕L←0

⎕LX←' ' ⍝ prototype...
  ⎕LX←0⍴⎕LX

⎕PP←10

⎕PR←' '

⎕PS←0

⎕PW←80

⎕R←0

⎕RL←3151369325420972410

⎕TZ←-5

⎕X←0