Spans of lenses

Michael Johnson, Robert Rosebrugh

Research output: Contribution to journalConference paperpeer-review

9 Citations (Scopus)


Corresponding to the variety of notions of asymmetric lens, various notions of symmetric lens have been proposed. A common theory of the various asymmetric and symmetric lenses should result from a study of spans of asymmetric lenses. In order to define a category whose arrows are spans of asymmetric lenses, the fact that a cospan of asymmetric lenses may not have a pullback must be dealt with. In this article, after resolving that problem we develop the functors which exhibit a category whose arrows are spans of wellbehaved lenses as a retract of a category whose arrows are the corresponding symmetric lenses. We relate them to the symmetric lenses of Hofmann, Pierce and Wagner.

Original languageEnglish
Pages (from-to)112-118
Number of pages7
JournalCEUR Workshop Proceedings
Publication statusPublished - 2014
EventJoint Workshops on International Conference on Extending Database Technology (EDBT 2014) and International Conference on Database Theory (ICDT 2014) - Athens, Greece
Duration: 28 Mar 201428 Mar 2014


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