# code: http://golf.shinh.org/reveal.rb?Count+in+Base+2/tails_1654148358&nbb
# target Nibbles version: 0.25
# commenter version: 0.1.2.181

#(implicit map):[[chr]] 
    < #(take):[[chr]] 
        $ #(= fstInt):int 
        >> #(tail):[[chr]] 
            `_ #(subsequences):[[chr]] 
                0 #(integer):int 
                + #(add):[chr] 
                    '`' #(char):chr 
                    , #(range from 1):[int] 
                        ~ #(auto = infinity):auto 
    \ #(reverse):[chr] <--arg( B:[chr] A:[chr] ) 
        #(implicit arg = B):[chr]