An introduction to K-theory for C*-algebras:
Gespeichert in:
1. Verfasser: | |
---|---|
Format: | Elektronisch E-Book |
Sprache: | English |
Veröffentlicht: |
Cambridge, UK
Cambridge University Press
2000
|
Schriftenreihe: | London Mathematical Society student texts
49 |
Schlagworte: | |
Online-Zugang: | FAW01 FAW02 Volltext |
Beschreibung: | Includes bibliographical references (p. 231-233) and indexes 1. C*-algebra theory -- 2. Projections and unitary elements -- 3. The K0-group of a unital C*-algebra -- 4. The functor K0 -- 5. The ordered Abelian group K0(A) -- 6. Inductive limit C*-algebras -- 7. Classification of AF-algebras -- 8. The functor K1 -- 9. The index map -- 10. The higher K-functors -- 11. Bott periodicity -- 12. The six-term exact sequence -- 13. Inductive limits of dimension drop algebras "Over the last 25 years K-theory has become an integrated part of the study of C*-algebras. This book gives an elementary introduction to this interesting and rapidly growing area of mathematics Fundamental to K-theory is the association of a pair of Abelian groups, K0(A) and K1(A), to each C*-algebra A. These groups reflect the properties of A in many ways. This book covers the basic properties of the functors K0 and K1 and their interrelationship. Applications of the theory include Elliott's classification theorem for AF-algebras, and it is shown that each pair of countable Abelian groups arises as the K-groups of some C*-algebra."--pub. desc |
Beschreibung: | 1 Online-Ressource (xii, 242 p.) |
ISBN: | 0511623801 0511826036 0521783348 0521789443 1107363098 1107368006 9780511623806 9780511826030 9780521783347 9780521789448 9781107363090 9781107368002 |
Internformat
MARC
LEADER | 00000nmm a2200000zcb4500 | ||
---|---|---|---|
001 | BV043056472 | ||
003 | DE-604 | ||
005 | 00000000000000.0 | ||
007 | cr|uuu---uuuuu | ||
008 | 151126s2000 |||| o||u| ||||||eng d | ||
020 | |a 0511623801 |c electronic bk. |9 0-511-62380-1 | ||
020 | |a 0511826036 |c ebook |9 0-511-82603-6 | ||
020 | |a 0521783348 |9 0-521-78334-8 | ||
020 | |a 0521789443 |9 0-521-78944-3 | ||
020 | |a 1107363098 |c electronic bk. |9 1-107-36309-8 | ||
020 | |a 1107368006 |9 1-107-36800-6 | ||
020 | |a 9780511623806 |c electronic bk. |9 978-0-511-62380-6 | ||
020 | |a 9780511826030 |c ebook |9 978-0-511-82603-0 | ||
020 | |a 9780521783347 |9 978-0-521-78334-7 | ||
020 | |a 9780521789448 |9 978-0-521-78944-8 | ||
020 | |a 9781107363090 |c electronic bk. |9 978-1-107-36309-0 | ||
020 | |a 9781107368002 |9 978-1-107-36800-2 | ||
035 | |a (OCoLC)831625390 | ||
035 | |a (DE-599)BVBBV043056472 | ||
040 | |a DE-604 |b ger |e aacr | ||
041 | 0 | |a eng | |
049 | |a DE-1046 |a DE-1047 | ||
082 | 0 | |a 512/.55 |2 22 | |
100 | 1 | |a Rørdam, M., (Mikael) |e Verfasser |4 aut | |
245 | 1 | 0 | |a An introduction to K-theory for C*-algebras |c M. Rørdam, F. Larsen, N. Laustsen |
264 | 1 | |a Cambridge, UK |b Cambridge University Press |c 2000 | |
300 | |a 1 Online-Ressource (xii, 242 p.) | ||
336 | |b txt |2 rdacontent | ||
337 | |b c |2 rdamedia | ||
338 | |b cr |2 rdacarrier | ||
490 | 0 | |a London Mathematical Society student texts |v 49 | |
500 | |a Includes bibliographical references (p. 231-233) and indexes | ||
500 | |a 1. C*-algebra theory -- 2. Projections and unitary elements -- 3. The K0-group of a unital C*-algebra -- 4. The functor K0 -- 5. The ordered Abelian group K0(A) -- 6. Inductive limit C*-algebras -- 7. Classification of AF-algebras -- 8. The functor K1 -- 9. The index map -- 10. The higher K-functors -- 11. Bott periodicity -- 12. The six-term exact sequence -- 13. Inductive limits of dimension drop algebras | ||
500 | |a "Over the last 25 years K-theory has become an integrated part of the study of C*-algebras. This book gives an elementary introduction to this interesting and rapidly growing area of mathematics | ||
500 | |a Fundamental to K-theory is the association of a pair of Abelian groups, K0(A) and K1(A), to each C*-algebra A. These groups reflect the properties of A in many ways. This book covers the basic properties of the functors K0 and K1 and their interrelationship. Applications of the theory include Elliott's classification theorem for AF-algebras, and it is shown that each pair of countable Abelian groups arises as the K-groups of some C*-algebra."--pub. desc | ||
650 | 4 | |a K-théorie | |
650 | 4 | |a C*-algèbres | |
650 | 7 | |a C* ÁLGEBRAS (ANÁLISE FUNCIONAL) |2 larpcal | |
650 | 7 | |a K-theorie |2 gtt | |
650 | 7 | |a C*-algebra's |2 gtt | |
650 | 7 | |a K-Theorie |2 swd | |
650 | 7 | |a C-Stern-Algebra |2 swd | |
650 | 7 | |a K-théorie |2 ram | |
650 | 7 | |a C*-algèbres |2 ram | |
650 | 7 | |a MATHEMATICS / Algebra / Linear |2 bisacsh | |
650 | 7 | |a C*-algebras |2 fast | |
650 | 7 | |a K-theory |2 fast | |
650 | 4 | |a K-theory | |
650 | 4 | |a C*-algebras | |
650 | 0 | 7 | |a C-Stern-Algebra |0 (DE-588)4136693-1 |2 gnd |9 rswk-swf |
650 | 0 | 7 | |a Algebraische K-Theorie |0 (DE-588)4141839-6 |2 gnd |9 rswk-swf |
689 | 0 | 0 | |a Algebraische K-Theorie |0 (DE-588)4141839-6 |D s |
689 | 0 | 1 | |a C-Stern-Algebra |0 (DE-588)4136693-1 |D s |
689 | 0 | |8 1\p |5 DE-604 | |
700 | 1 | |a Larsen, F. |e Sonstige |4 oth | |
700 | 1 | |a Laustsen, N. |e Sonstige |4 oth | |
856 | 4 | 0 | |u http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=551362 |x Aggregator |3 Volltext |
912 | |a ZDB-4-EBA | ||
999 | |a oai:aleph.bib-bvb.de:BVB01-028480664 | ||
883 | 1 | |8 1\p |a cgwrk |d 20201028 |q DE-101 |u https://d-nb.info/provenance/plan#cgwrk | |
966 | e | |u http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=551362 |l FAW01 |p ZDB-4-EBA |q FAW_PDA_EBA |x Aggregator |3 Volltext | |
966 | e | |u http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=551362 |l FAW02 |p ZDB-4-EBA |q FAW_PDA_EBA |x Aggregator |3 Volltext |
Datensatz im Suchindex
_version_ | 1804175428408049664 |
---|---|
any_adam_object | |
author | Rørdam, M., (Mikael) |
author_facet | Rørdam, M., (Mikael) |
author_role | aut |
author_sort | Rørdam, M., (Mikael) |
author_variant | m m r mm mmr |
building | Verbundindex |
bvnumber | BV043056472 |
collection | ZDB-4-EBA |
ctrlnum | (OCoLC)831625390 (DE-599)BVBBV043056472 |
dewey-full | 512/.55 |
dewey-hundreds | 500 - Natural sciences and mathematics |
dewey-ones | 512 - Algebra |
dewey-raw | 512/.55 |
dewey-search | 512/.55 |
dewey-sort | 3512 255 |
dewey-tens | 510 - Mathematics |
discipline | Mathematik |
format | Electronic eBook |
fullrecord | <?xml version="1.0" encoding="UTF-8"?><collection xmlns="http://www.loc.gov/MARC21/slim"><record><leader>04065nmm a2200769zcb4500</leader><controlfield tag="001">BV043056472</controlfield><controlfield tag="003">DE-604</controlfield><controlfield tag="005">00000000000000.0</controlfield><controlfield tag="007">cr|uuu---uuuuu</controlfield><controlfield tag="008">151126s2000 |||| o||u| ||||||eng d</controlfield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">0511623801</subfield><subfield code="c">electronic bk.</subfield><subfield code="9">0-511-62380-1</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">0511826036</subfield><subfield code="c">ebook</subfield><subfield code="9">0-511-82603-6</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">0521783348</subfield><subfield code="9">0-521-78334-8</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">0521789443</subfield><subfield code="9">0-521-78944-3</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">1107363098</subfield><subfield code="c">electronic bk.</subfield><subfield code="9">1-107-36309-8</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">1107368006</subfield><subfield code="9">1-107-36800-6</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">9780511623806</subfield><subfield code="c">electronic bk.</subfield><subfield code="9">978-0-511-62380-6</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">9780511826030</subfield><subfield code="c">ebook</subfield><subfield code="9">978-0-511-82603-0</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">9780521783347</subfield><subfield code="9">978-0-521-78334-7</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">9780521789448</subfield><subfield code="9">978-0-521-78944-8</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">9781107363090</subfield><subfield code="c">electronic bk.</subfield><subfield code="9">978-1-107-36309-0</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">9781107368002</subfield><subfield code="9">978-1-107-36800-2</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(OCoLC)831625390</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(DE-599)BVBBV043056472</subfield></datafield><datafield tag="040" ind1=" " ind2=" "><subfield code="a">DE-604</subfield><subfield code="b">ger</subfield><subfield code="e">aacr</subfield></datafield><datafield tag="041" ind1="0" ind2=" "><subfield code="a">eng</subfield></datafield><datafield tag="049" ind1=" " ind2=" "><subfield code="a">DE-1046</subfield><subfield code="a">DE-1047</subfield></datafield><datafield tag="082" ind1="0" ind2=" "><subfield code="a">512/.55</subfield><subfield code="2">22</subfield></datafield><datafield tag="100" ind1="1" ind2=" "><subfield code="a">Rørdam, M., (Mikael)</subfield><subfield code="e">Verfasser</subfield><subfield code="4">aut</subfield></datafield><datafield tag="245" ind1="1" ind2="0"><subfield code="a">An introduction to K-theory for C*-algebras</subfield><subfield code="c">M. Rørdam, F. Larsen, N. Laustsen</subfield></datafield><datafield tag="264" ind1=" " ind2="1"><subfield code="a">Cambridge, UK</subfield><subfield code="b">Cambridge University Press</subfield><subfield code="c">2000</subfield></datafield><datafield tag="300" ind1=" " ind2=" "><subfield code="a">1 Online-Ressource (xii, 242 p.)</subfield></datafield><datafield tag="336" ind1=" " ind2=" "><subfield code="b">txt</subfield><subfield code="2">rdacontent</subfield></datafield><datafield tag="337" ind1=" " ind2=" "><subfield code="b">c</subfield><subfield code="2">rdamedia</subfield></datafield><datafield tag="338" ind1=" " ind2=" "><subfield code="b">cr</subfield><subfield code="2">rdacarrier</subfield></datafield><datafield tag="490" ind1="0" ind2=" "><subfield code="a">London Mathematical Society student texts</subfield><subfield code="v">49</subfield></datafield><datafield tag="500" ind1=" " ind2=" "><subfield code="a">Includes bibliographical references (p. 231-233) and indexes</subfield></datafield><datafield tag="500" ind1=" " ind2=" "><subfield code="a">1. C*-algebra theory -- 2. Projections and unitary elements -- 3. The K0-group of a unital C*-algebra -- 4. The functor K0 -- 5. The ordered Abelian group K0(A) -- 6. Inductive limit C*-algebras -- 7. Classification of AF-algebras -- 8. The functor K1 -- 9. The index map -- 10. The higher K-functors -- 11. Bott periodicity -- 12. The six-term exact sequence -- 13. Inductive limits of dimension drop algebras</subfield></datafield><datafield tag="500" ind1=" " ind2=" "><subfield code="a">"Over the last 25 years K-theory has become an integrated part of the study of C*-algebras. This book gives an elementary introduction to this interesting and rapidly growing area of mathematics</subfield></datafield><datafield tag="500" ind1=" " ind2=" "><subfield code="a">Fundamental to K-theory is the association of a pair of Abelian groups, K0(A) and K1(A), to each C*-algebra A. These groups reflect the properties of A in many ways. This book covers the basic properties of the functors K0 and K1 and their interrelationship. Applications of the theory include Elliott's classification theorem for AF-algebras, and it is shown that each pair of countable Abelian groups arises as the K-groups of some C*-algebra."--pub. desc</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">K-théorie</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">C*-algèbres</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">C* ÁLGEBRAS (ANÁLISE FUNCIONAL)</subfield><subfield code="2">larpcal</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">K-theorie</subfield><subfield code="2">gtt</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">C*-algebra's</subfield><subfield code="2">gtt</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">K-Theorie</subfield><subfield code="2">swd</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">C-Stern-Algebra</subfield><subfield code="2">swd</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">K-théorie</subfield><subfield code="2">ram</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">C*-algèbres</subfield><subfield code="2">ram</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">MATHEMATICS / Algebra / Linear</subfield><subfield code="2">bisacsh</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">C*-algebras</subfield><subfield code="2">fast</subfield></datafield><datafield tag="650" ind1=" " ind2="7"><subfield code="a">K-theory</subfield><subfield code="2">fast</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">K-theory</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">C*-algebras</subfield></datafield><datafield tag="650" ind1="0" ind2="7"><subfield code="a">C-Stern-Algebra</subfield><subfield code="0">(DE-588)4136693-1</subfield><subfield code="2">gnd</subfield><subfield code="9">rswk-swf</subfield></datafield><datafield tag="650" ind1="0" ind2="7"><subfield code="a">Algebraische K-Theorie</subfield><subfield code="0">(DE-588)4141839-6</subfield><subfield code="2">gnd</subfield><subfield code="9">rswk-swf</subfield></datafield><datafield tag="689" ind1="0" ind2="0"><subfield code="a">Algebraische K-Theorie</subfield><subfield code="0">(DE-588)4141839-6</subfield><subfield code="D">s</subfield></datafield><datafield tag="689" ind1="0" ind2="1"><subfield code="a">C-Stern-Algebra</subfield><subfield code="0">(DE-588)4136693-1</subfield><subfield code="D">s</subfield></datafield><datafield tag="689" ind1="0" ind2=" "><subfield code="8">1\p</subfield><subfield code="5">DE-604</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Larsen, F.</subfield><subfield code="e">Sonstige</subfield><subfield code="4">oth</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Laustsen, N.</subfield><subfield code="e">Sonstige</subfield><subfield code="4">oth</subfield></datafield><datafield tag="856" ind1="4" ind2="0"><subfield code="u">http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=551362</subfield><subfield code="x">Aggregator</subfield><subfield code="3">Volltext</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">ZDB-4-EBA</subfield></datafield><datafield tag="999" ind1=" " ind2=" "><subfield code="a">oai:aleph.bib-bvb.de:BVB01-028480664</subfield></datafield><datafield tag="883" ind1="1" ind2=" "><subfield code="8">1\p</subfield><subfield code="a">cgwrk</subfield><subfield code="d">20201028</subfield><subfield code="q">DE-101</subfield><subfield code="u">https://d-nb.info/provenance/plan#cgwrk</subfield></datafield><datafield tag="966" ind1="e" ind2=" "><subfield code="u">http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=551362</subfield><subfield code="l">FAW01</subfield><subfield code="p">ZDB-4-EBA</subfield><subfield code="q">FAW_PDA_EBA</subfield><subfield code="x">Aggregator</subfield><subfield code="3">Volltext</subfield></datafield><datafield tag="966" ind1="e" ind2=" "><subfield code="u">http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=551362</subfield><subfield code="l">FAW02</subfield><subfield code="p">ZDB-4-EBA</subfield><subfield code="q">FAW_PDA_EBA</subfield><subfield code="x">Aggregator</subfield><subfield code="3">Volltext</subfield></datafield></record></collection> |
id | DE-604.BV043056472 |
illustrated | Not Illustrated |
indexdate | 2024-07-10T07:16:08Z |
institution | BVB |
isbn | 0511623801 0511826036 0521783348 0521789443 1107363098 1107368006 9780511623806 9780511826030 9780521783347 9780521789448 9781107363090 9781107368002 |
language | English |
oai_aleph_id | oai:aleph.bib-bvb.de:BVB01-028480664 |
oclc_num | 831625390 |
open_access_boolean | |
owner | DE-1046 DE-1047 |
owner_facet | DE-1046 DE-1047 |
physical | 1 Online-Ressource (xii, 242 p.) |
psigel | ZDB-4-EBA ZDB-4-EBA FAW_PDA_EBA |
publishDate | 2000 |
publishDateSearch | 2000 |
publishDateSort | 2000 |
publisher | Cambridge University Press |
record_format | marc |
series2 | London Mathematical Society student texts |
spelling | Rørdam, M., (Mikael) Verfasser aut An introduction to K-theory for C*-algebras M. Rørdam, F. Larsen, N. Laustsen Cambridge, UK Cambridge University Press 2000 1 Online-Ressource (xii, 242 p.) txt rdacontent c rdamedia cr rdacarrier London Mathematical Society student texts 49 Includes bibliographical references (p. 231-233) and indexes 1. C*-algebra theory -- 2. Projections and unitary elements -- 3. The K0-group of a unital C*-algebra -- 4. The functor K0 -- 5. The ordered Abelian group K0(A) -- 6. Inductive limit C*-algebras -- 7. Classification of AF-algebras -- 8. The functor K1 -- 9. The index map -- 10. The higher K-functors -- 11. Bott periodicity -- 12. The six-term exact sequence -- 13. Inductive limits of dimension drop algebras "Over the last 25 years K-theory has become an integrated part of the study of C*-algebras. This book gives an elementary introduction to this interesting and rapidly growing area of mathematics Fundamental to K-theory is the association of a pair of Abelian groups, K0(A) and K1(A), to each C*-algebra A. These groups reflect the properties of A in many ways. This book covers the basic properties of the functors K0 and K1 and their interrelationship. Applications of the theory include Elliott's classification theorem for AF-algebras, and it is shown that each pair of countable Abelian groups arises as the K-groups of some C*-algebra."--pub. desc K-théorie C*-algèbres C* ÁLGEBRAS (ANÁLISE FUNCIONAL) larpcal K-theorie gtt C*-algebra's gtt K-Theorie swd C-Stern-Algebra swd K-théorie ram C*-algèbres ram MATHEMATICS / Algebra / Linear bisacsh C*-algebras fast K-theory fast K-theory C*-algebras C-Stern-Algebra (DE-588)4136693-1 gnd rswk-swf Algebraische K-Theorie (DE-588)4141839-6 gnd rswk-swf Algebraische K-Theorie (DE-588)4141839-6 s C-Stern-Algebra (DE-588)4136693-1 s 1\p DE-604 Larsen, F. Sonstige oth Laustsen, N. Sonstige oth http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=551362 Aggregator Volltext 1\p cgwrk 20201028 DE-101 https://d-nb.info/provenance/plan#cgwrk |
spellingShingle | Rørdam, M., (Mikael) An introduction to K-theory for C*-algebras K-théorie C*-algèbres C* ÁLGEBRAS (ANÁLISE FUNCIONAL) larpcal K-theorie gtt C*-algebra's gtt K-Theorie swd C-Stern-Algebra swd K-théorie ram C*-algèbres ram MATHEMATICS / Algebra / Linear bisacsh C*-algebras fast K-theory fast K-theory C*-algebras C-Stern-Algebra (DE-588)4136693-1 gnd Algebraische K-Theorie (DE-588)4141839-6 gnd |
subject_GND | (DE-588)4136693-1 (DE-588)4141839-6 |
title | An introduction to K-theory for C*-algebras |
title_auth | An introduction to K-theory for C*-algebras |
title_exact_search | An introduction to K-theory for C*-algebras |
title_full | An introduction to K-theory for C*-algebras M. Rørdam, F. Larsen, N. Laustsen |
title_fullStr | An introduction to K-theory for C*-algebras M. Rørdam, F. Larsen, N. Laustsen |
title_full_unstemmed | An introduction to K-theory for C*-algebras M. Rørdam, F. Larsen, N. Laustsen |
title_short | An introduction to K-theory for C*-algebras |
title_sort | an introduction to k theory for c algebras |
topic | K-théorie C*-algèbres C* ÁLGEBRAS (ANÁLISE FUNCIONAL) larpcal K-theorie gtt C*-algebra's gtt K-Theorie swd C-Stern-Algebra swd K-théorie ram C*-algèbres ram MATHEMATICS / Algebra / Linear bisacsh C*-algebras fast K-theory fast K-theory C*-algebras C-Stern-Algebra (DE-588)4136693-1 gnd Algebraische K-Theorie (DE-588)4141839-6 gnd |
topic_facet | K-théorie C*-algèbres C* ÁLGEBRAS (ANÁLISE FUNCIONAL) K-theorie C*-algebra's K-Theorie C-Stern-Algebra MATHEMATICS / Algebra / Linear C*-algebras K-theory Algebraische K-Theorie |
url | http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&AN=551362 |
work_keys_str_mv | AT rørdammmikael anintroductiontoktheoryforcalgebras AT larsenf anintroductiontoktheoryforcalgebras AT laustsenn anintroductiontoktheoryforcalgebras |