# code: http://golf.shinh.org/reveal.rb?Shifting+Pattern+Fixed/tails_1646611779&nbb
# target Nibbles version: 0.25
# commenter version: 0.1.2.181

`. #(iterate while uniq):[[chr]] 
    fstLine #(@):[chr] 
    \A 
    : #(append):[chr] 
        `( #(uncons):chr 
            \ #(reverse):[chr] 
                A #($):[chr] 
        sets B 
        \ #(reverse):[chr] 
            #(implicit arg = B):[chr]