equal.in

[+>]+>[+>] increase both strings and space in between
<[<]> to the start
include(copy.bf)
[>]>[>]< to the copy end
[[>>+<<-]<] shift the copy two cells right
>>>[>]< to the copy end
[-<]> subtract one to get initial strings
include(interleave.bf)
<<+>> set equality flag
TODO: Check the length inequality and shortcircuit to inequality case
[ equality bruteforce loop
 [>-<-] subtract both first and second string characters
 >[ if second string character nonzero (not equal)
  [-]<<<[-]>>> kill second character and equality flag
 ]
 >[[<<+>>-]>] shift the remaining contiguous part to the left
 >[ if spreadout remains are there (cannot be equal then):
  * destroy them
  [>>]<<[[-]<<]
  * destroy contiguous part
  <<[[-]<]
  * and kill equality flag
  <[-]
  * and get back to the "spreadout" part (now empty)
  >>>>>
 ]
 <<<<[<]> to the contiguous part
]
<<[<+>-] copy the equality flag closer
<< to the string
[ finalization loop
 -[>>+<<-] subtract one from the string and copy it over the equality flag
 >[<+>-] copy the equality flag closer
 << to the next char
]
> to the equality flag