Uniq←{
  0=⍴⍴⍵:,⍵
  X←⍵
  c←{⊂⍵}⌸ ⍺⍺ ⍵
  ⍵ ⌷⍨⊂ {⍵[⍋⍵]} ∊ {1≥≢⍵:⍵ ⋄ (⊃⍵)⍪∇ ⍵⌿⍨(X⌷⍨⊂⍵)≢⍤¯1 999⊢(X⌷⍨⊃⍵)}¨ c
}

HASH←{
  N←≢X←⍺ ⋄ Y←⍵ ⋄ Z←(≢⍵)⍴¯1
  c←{⊂⍵}⌸ ⍺⍺ ⍺⍪⍵
  Z ⊣ {k←(N>⍵)⍳0 ⋄ Z[q]←(p,N)[(X⌷⍨⊂p←k↑⍵) ⍳ Y⌷⍨⊂q←k↓⍵-N] ⋄ 0}¨ c
}