Corrigendum to “Some problems of Wielandt revisited” [J. Algebra 302 (1) (2006) 167–185]

An error in the proof of Theorem 2 in [W. Knapp, Some problems of Wielandt revisited, J. Algebra 302 (1) (2006) 167–185] (concerning the action of semisimple groups) is corrected.     

Corrigendum to “Liouvillian solutions of first order nonlinear differential equations” [J. Pure Appl. Algebra 221 (2) (2017) 411–421]

The purpose of this erratum is to provide a correct proof for the first part of Theorem 2.2 of the paper ([3]) referred to in the title.     

Corrigendum to “A Schneider type theorem for Hopf algebroids” [J. Algebra 318 (1) (2007) 225–269]

In our paper we heavily used the result that two constituent bialgebroids in a Hopf algebroid possess isomorphic comodule categories. This statement was based on [T. Brzeziński, A note on coring extensions, Ann. Univ. Ferrara Sez. VII Sci. Mat. LI (2005) 15–27. A corrected version is available at http://arxiv.org/abs/math/0410020v3, Theorem 2.6], whose proof turned out to contain an unjustified step. Here we prove the main results in our paper without using [T. Brzeziński, A note on coring extensions, Ann. Univ. Ferrara Sez. VII Sci. Mat. LI (2005) 15–27. A corrected version is available at http://arxiv.org/abs/math/0410020v3, Theorem 2.6] and the derived isomorphism of comodule categories.     

Corrigendum to “Computing of the number of right coideal subalgebras of Uq(so2n+1)” [J. Algebra 341 (1) (2011) 279–296]

Adjoint functors and projectivization in representation theory of partially ordered sets are used to generalize the algorithms of differentiation by a maximal and by a minimal point. Conceptual explanations are given for the combinatorial construction of the derived set and for the differentiation functor.     

Corrigendum to “Almost-Ramanujan graphs and prime gaps” [European J. Combin. 43 (2015) 204–209]

In an earlier paper Dudek (2015), the present author proposed a simple way to construct families of almost-Ramanujan graphs. The purpose of this note is to point out a crucial error in the construction and discuss what results can be salvaged.     

Corrigendum to “Property (gb) and perturbations” [J. Math. Anal. Appl. 383 (1) (2011) 82–94]

We give a complete reference for work cited in [M.H.M. Rashid, Property (gb) and perturbations, J. Math. Anal. Appl. 383 (1) (2011) 82–94].     

Corrigendum to “Maximal linear groups induced on the Frattini quotient of a p-group” [J. Pure Appl. Algebra 222 (10) (2018) 2931–2951]

We give a correction to Fig. 1 and supporting text published in the paper: ‘Maximal linear groups induced on the Frattini quotient of a p-group’, J. Pure Appl. Algebra 222 (10) (2018) 2931–2951.     

Corrigendum to “Belief functions contextual discounting and canonical decompositions” [International Journal of Approximate Reasoning 53 (2012) 146–158]

Proposition 4 and Theorem 1 of the article “Belief functions contextual discounting and canonical decompositions” [International Journal of Approximate Reasoning 53 (2012) 146–158] provide an erroneous result. We give here the true result with a correct proof.