Abstract. We study the microlocal properties of bisingular operators, a class of operators on the product of two compact manifolds. We define a wave front set for such operators, and analyse its properties. We compare our wave front set with the SG wave front set, a global wave front set which shares with it formal similarities.

Abstract. For operators belonging either to a class of global bisingular pseudodifferential operators on R m ×R n or to a class of bisingular pseudodifferential operators on a product M × N of two closed smooth manifolds, we show the equivalence of their ellipticity (defined by the invertibility of certain operatorvalued, homogeneous principal symbols) and their Fredholm mapping property in associated scales of Sobolev spaces. We also prove the spectral invariance of these operator classes and then extend these results to larger classes of Toeplitz type operators.

In this paper we study the accessibility by visually impaired people of the Learning Management System (LMS) Moodle 2. The study is conducted by testing four different visually impaired subjects, with different degrees of disability and performing different tasks connected to different roles in the LMS. A peculiar focus is given to the accessibility of content involving mathematics. At the end of the paper some recommendations to improve the accessibility of Moodle 2 are given.

Abstract. We study the asymptotic behavior of the counting function of tensor products of operators, in the cases where the factors are either pseudodifferential operators on closed manifolds, or pseudodifferential operators of Shubin type on R n , respectively. We obtain, in particular, the sharpness of the remainder term in the corresponding Weyl formulae, which we prove by means of the analysis of some explicit examples.

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