message: Add some more type checking tests
diff: % Universes
  -
  - % Unit
  +>> synth_type universe Type ?
  +>> Impossible.
  % Functions
  % Binary format descriptions
  +>> synth_type format_type Type ?
  +>> Impossible.
  +
  +>> synth_type (format_intro_array format_intro_u8 (int_intro 3)) Type ?
  +>> Yes:
  +>> Type := semantics.format_type.
  +
  >> synth_type (format_elim (format_intro_array format_intro_u8 (int_intro 3))) Type ?
  >> Yes:
  >> Type := semantics.universe.
  