#incomplete

References

  1. https://en.wikipedia.org/wiki/Sentence_(mathematical_logic)
  2. M. Avanzini, Lecture Notes, Topic: “weak monadic second-order logic (WMSO).” M1-AL, Centre Inria d’Université Côte d’Azur, 2021. https://www-sop.inria.fr/members/Martin.Avanzini/teaching/2021/AL/slides/w2.pdf