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