# code: http://golf.shinh.org/reveal.rb?Stepping+Space+Removal/tails_1645190195&nbb
# target Nibbles version: 0.23
# commenter version: 0.1.2.181

`. #(iterate while uniq):[[chr]] 
    @ #(= fstLine):[chr] 
    - #(diff):[chr] <--arg( A:[chr] ) 
        $ #(= A):[chr] 
        " " #(string):[chr]