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# Square Original Of (`⊐`)
    
## `⊐ 𝕩`: Classify  
    
First index of each major cell of `𝕩` in `𝕩`.
    
           ⊐ 5‿6‿2‿2‿5‿1

           a ← 3‿3 ⥊ 0‿1‿2‿9‿0‿9‿0‿1‿2

           ⊐ a

    
    
## `𝕨 ⊐ 𝕩`: Index Of
    
First index of each major cell of `𝕩` in `𝕨`. Rank of `𝕩` must be at least cell rank of 𝕨`.
    
If a cell is not found in `𝕨`, that position will contain the length of `𝕨` (`≠𝕨`). 
    
           5‿6‿2‿2‿5‿1 ⊐ 5‿2‿1‿6

           a ← 3‿3 ⥊ 0‿1‿2‿9‿0‿9‿0‿1‿2

           a ⊐ ⟨9‿0‿9⟩