Problem: Guess what it does

Code: Guess+what+it+does/tails_1646492097

Nibbles version: 0.2 | 0.21 | 0.22 | 0.23 | 0.24 | 0.25 | 1.00

Format: Compact | Simple | +Type | Table | JSON | .nbl (DeBruijn) | .nbl (names)

: (append):[[int]] 
    : (append):[int] 
        \ (reverse):[int] 
            ; (save):[int] -->let( A:[int] ) 
                : (append):[int] 
                    `, (range from 0):[int] 
                        13 (integer):int 
                    + (add):[int] 
                        19 (integer):int 
                        , (range from 1):[int] 
                            237 (integer):int 
        $ (= A):[int] 
    ~ (auto = []):auto