Why are Modal Logics so Robustly Decidable?

Erich Grädel. Why are Modal Logics so Robustly Decidable?. Bulletin of the EATCS, 68:90-103, 1999.

@article{Gradel99:1,
  title = {Why are Modal Logics so Robustly Decidable?},
  author = {Erich Grädel},
  year = {1999},
  tags = {modal logic, logic},
  researchr = {https://researchr.org/publication/Gradel99%3A1},
  cites = {0},
  citedby = {0},
  journal = {Bulletin of the EATCS},
  volume = {68},
  pages = {90-103},
}