salle A. Turing CE4
5 avril 2012 - 14h00
Playing in the Grey Area of Proofs
par Laura Kovacs de Technical University of Vienna
Abstract: nterpolation is an important technique in verification and static
analysis of programs. In particular, interpolants extracted from
proofs of various properties are used in invariant generation and
bounded model checking. A number of recent papers studies
interpolation in various theories and also extraction of smaller
interpolants from proofs. In particular, there are several algorithms
for extracting of interpolants from so-called local proofs.
In this talk we describe a technique of minimising interpolants based
on transformations of what we call the “grey area” of local proofs. We
also present how to translate arbitrary proofs, under certain common
conditions, into local ones.
Unlike many other interpolation techniques, our technique is very
general and applies to arbitrary theories. Our approach is implemented
in the theorem prover Vampire and evaluated on a large number of
benchmarks coming from first-order theorem proving and bounded model
checking using logic with equality, uninterpreted functions and linear
arithmetic. Our experiments demonstrate the power of the new
techniques: for example, it is not unusual that our proof
transformation gives more than a tenfold reduction in the size of
interpolants.
This is a joint work with Krystof Hoder and Andrei Voronkov (The
University of Manchester).
