1. An introduction to inductive definitions;Aczel,1977
2. An arithmetical hierarchy of the law of excluded middle and related principles;Akama,2004
3. A formalization of the strong normalization proof for system F in LEGO;Altenkirch,1993
4. Ramsey interpreted: a parametric version of Ramsey's Theorem;Bellin,1990
5. Proving termination of programs having transition invariants of height ω;Berardi,2014