We look at the Lp bounds on eigenfunctions for polygonal domains (or more generally Euclidean surfaces with conic singularities) by analysis of the wave operator on the flat Euclidean cone C(Sρ) def = R+ × ( R / 2πρZ ) of radius ρ > 0 equipped with the metric h(r, θ) = dr2 + r2 dθ2. Using explicit oscillatory integrals and relying on the fundamental solution to the wave equation in geometric re...

We explore ideal models for a programming language with recursive polymorphic types, variants of the model studied by MacQueen, Plotkin, and Sethi. The use of suitable ideals yields a close t between models and programming language. Two of our semantics of type expressions are faithful, in the sense that programs that behave identically in all contexts have exactly the same types.

Recently, a standardization theorem has been proven for a variant of Plotkin’s call-by-value lambda-calculus extended by means of two commutation rules (sigma-reductions): this result was based on a partitioning between head and internal reductions. We study the head normalization for this call-by-value calculus with sigma-reductions and we relate it to the weak evaluation of original Plotkin’s...

It is well known that the language obtained by deleting an arbitrary language from a regular language is regular. We give an upper bound for the state complexity of deleting an arbitrary language from a regular language and a matching lower bound. We show that the state complexity of deletion is n · 2n−1 (respectively, (n + 1 2 ) · 2 − 2) when using complete (respectively, incomplete) determini...