assumption
  have <space>
  have_chars " "
  have_range "a" "z"
end assumption

# (assumption (@ 1 0-10)
#   (.inner
#     (have (@ 2 2-6)
#       (.data
#         (keys (@ 2 7-14) ‘<space>’)
#       )
#     )
#     (have_chars (@ 3 2-12) ‘" "’)
#     (have_range (@ 4 2-12) ‘"a"’ ‘"z"’)
#   )
# )