Cc Τ on stage: Generalised uniform equivalence testing for verifying student assignment solutions

Abstract

The tool cc Τ is an implementation for testing various parameterised notions of program correspondence between logic programs under the answer-set semantics, based on reductions to quantified propositional logic. One such notion is relativised uniform equivalence with projection, which extends standard uniform equivalence via two additional parameters: one for specifying the input alphabet and one for specifying the output alphabet. In particular, the latter parameter is used for projecting answer sets to the set of designated output atoms, i.e. ignoring auxiliary atoms during answer-set comparison. In this paper, we discuss an application of cc Τ for verifying the correctness of students' solutions drawn from a laboratory course on logic programming, employing relativised uniform equivalence with projection as the underlying program correspondence notion. We complement our investigation by discussing a performance evaluation of cc Τ, showing that discriminating among different back-end solvers for quantified propositional logic is a crucial issue towards optimal performance. © 2009 Springer Berlin Heidelberg.