Abstract The use of propositional logic and systems linear inequalities over reals is a common means to model software for formal verification. Craig interpolants constitute central building block in this setting over-approximating reachable states, e.g. as candidates inductive loop invariants. Interpolants system can be efficiently computed from Simplex refutation by applying the Farkas’ lemma...

We develop algorithms for computing Craig interpolants for first-order formulas over real numbers with a wide range of nonlinear functions, including transcendental functions and differential equations. We transform proof traces from δ-complete decision procedures into interpolants that consist of Boolean combinations of linear constraints. The algorithms are guaranteed to find the interpolants...

Interpolation (together with completeness and decidability) has become one of the standard properties that logicians investigate when designing a logic. In this paper, we provide strong evidence that the presence of interpolants is not only cogent for scientific reasoning but has also important practical implications in computer science. We illustrate that interpolation in general, and uniform ...

We present ongoing work to extend proof tree preserving interpolation to inductive sequences and tree interpolants. We present an algorithm to compute tree interpolants inductively over a resolution proof. Correctness of the algorithm is justified by the concept of partial tree interpolants and the appropriate definition of a projection function for conjunctions of literals onto nodes of the tr...

We study uniform interpolation and forgetting in the description logic ALC. Our main results are model-theoretic characterizations of uniform interpolants and their existence in terms of bisimulations, tight complexity bounds for deciding the existence of uniform interpolants, an approach to computing interpolants when they exist, and tight bounds on their size. We use a mix of modeltheoretic a...

For the problem of constructing smooth functions over arbitrary surfaces from discrete data, we propose to use Loop’s subdivision functions as the interpolants. Results on the existence, uniqueness and error bound of the interpolants are established. An efficient progressive computation algorithm for the interpolants is also presented. Mathematics subject classification:

This paper describes the Vinter tool for extracting interpolants from proofs and minimising such interpolants using various measures. Vinter takes an input problem written in either SMT-LIB or TPTP syntax, generates so called local proofs and then uses a technique of playing in the grey areas of proofs to find interpolants minimal with respect to various measures. Proofs are found using either ...

Spline quasi-interpolants with best approximation orders and small norms are useful in several applications. In this paper, we construct the so-called near-best discrete and integral quasi-interpolants based on H-splines, i.e., B-splines with regular hexagonal supports on the uniform three-directional mesh of the plane. These quasi-interpolants are obtained so as to be exact on some space of po...

We introduce a general definition of refinable Hermite interpolants and investigate their general properties. We study also a notion of symmetry of these refinable interpolants. Results and ideas from the extensive theory of general refinement equations are applied to obtain results on refinable Hermite interpolants. The theory developed here is constructive and yields an easy-to-use constructi...