Structural logical relations with case analysis and equality reasoning
Ulrik Terp Rasmussen, Andrzej Filinski · 2013
Formalizing proofs by logical relations in the Twelf proof assistant is known to be notoriously difficult. However, as demonstrated by Schürmann and Sarnat [In Proc. of 23rd Symp. on Logic in Computer Science, 2008] such proofs can be represented and verified in Twelf if done so using a Gentzen-style auxiliary assertion logic which is subsequently proved consistent via cut elimination.