On Ordinal Notations . This contribution contains data structures for ordinals less than Gamma0 under Cantor and Veblen normal forms. Well-foundedness is established thanks to RPO with status for generic terms. This contribution also includes termination proofs of Hydra battles and Goodstein sequences as well as a computation of the length of the Goodstein sequence starting from 4 in base 2. This work is supported by INRIA-Futurs (Logical project-team), CNRS and the French ANR via the A3PAT project (http://www3.iie.cnam.fr/~urbain/a3pat/).
opam install coq-cantor.8.5.0