This statement by Jiri Adamek, Jan Rutten and Yde Venemais is provided as an addition to the ZBMath review of
Denecke, Klaus; Wismath, Shelly L.:
Universal algebra and coalgebra.
Hackensack, NJ: World Scientific, ISBN 978-981-283-745-5/hbk (2009; Zbl review).


This statement concerns the resemblance of [DW], the recently published book
"Universal Algebra and Coalgebra" by K. Denecke and S. Wismath [Hackensack, NJ:
World Scientific (2009; Zbl 1176.08001)], to [G], the text "Universelle Coalgebra"
by H. P. Gumm, which was published as an appendix to the book "Allgemeine Algebra"
by Th. Ihringer [Berliner Studienreihe zur Mathematik 10; Lemgo: Heldermann Verlag
(2003; Zbl 1036.08001)].

The resemblance between the two texts, at each level of organisation, is
striking. [DW] contains 12 chapters, of which the chapters 2,3,4,7,8 and 9
are about coalgebra. Of these, all but the last one are completely based
on [G], in the following sense:
1 At the level of overall organisation, the table of contents
  of these chapters is virtually the same as that of [G].
2 Individual chapters of [DW] are organized in almost
  the same manner as the corresponding sections of [G]. For instance,
  (a) In chapter 2 of [DW] all 11 sections but 2.5 and 2.9 correspond
      one-to-one to the  sections of Section 1.1 - 1.8 of [G];
  (b) Modulo some minor reorganisation, the 10 sections of chapter 4 of [DW]
      directly correspond to the sections 3.0 - 3.8 of [G];
  (c) Chapter 7 of [DW] follows the build-up of the sections 4.1-4.4 of [G];
  (d) Chapter 8 that of 4.5-4.7.
3 At the level of sections, the authors of [DW] in a number of cases copy
  the structure of the corresponding parts of [G]; to name just a few:
  (a) the sections 4.3 and 4.4 of [DW] are clear copies of section 3.2 in [G];
  (b) the sections 2.1-2.4 and 2.6-2.8 of [DW] are clear copies of the
      sections 1.1-1.7 of [G]
4 At the level of paragraphs, a large part of the text of [DW] consists of
  sentence by sentence translation of material from [G]; for example: pages
  48-50 in [DW] are translations of the corresponding text of pages 166-168
  of [G].
5 At the level of individual examples, notation, etc it becomes even more
  clear to which degree the material on coalgebra in [DW] is taken from [G]:
  most of the names of variables, most diagrams, etc., in [DW] are exactly
  as in [G].
Note that [G] is not cited as a source for [DW]. The only credits to [G] are
given for Lemma 4.1.4 and for (an insignificant) Lemma 7.5.2.

Summarizing, we can describe the mentioned chapters of [DW] as
the translated version of [G], with minor modifications, and
reorganizations of the material
. There can be no doubt whatsoever
that the intellectual ownership of the material resides with H. Peter Gumm.

Jiri Adamek, Jan Rutten and Yde Venema