Abstract. In this paper we provide a simple proof of the extension theorem for partial orderings due to Suzumura [1983] when the domain of the partial order is finite. The extensio...
This paper describes formalizations of Tait’s normalization proof for the simply typed λ-calculus in the proof assistants Minlog, Coq and Isabelle/HOL. From the formal proofs p...
Abstract. Quantified Boolean formulae (QBF) allow compact encoding of many decision problems. Their importance motivated the development of fast QBF solvers. Certifying the result...
Placing our result in a web of related mechanised results, we give a direct proof that the de Bruijn λ-calculus (`a la Huet, Nipkow and Shankar) is isomorphic to an α-quotiented ...
Abstract. We prove "untyping" theorems: in some typed theories (semirings, Kleene algebras, residuated lattices, involutive residuated lattices), typed equations can be d...