(1) : 2

# (map (@ 1 0-0)
#   (.sequence
#     (string (@ 1 1-2) ‘1’)
#   )
#   (.result
#     (string (@ 1 6-7) ‘2’)
#   )
# )
# :1:0–1: warning: singleton unordered subsequence
#  (1) : 2
#  ^