Editing History of topos theory (section)

==Summary==
The ''topos'' concept arose in algebraic geometry, as a consequence of combining the concept of ''sheaf'' and ''closure under categorical operations''. It plays a certain definite role in cohomology theories. A 'killer application' is [[étale cohomology]].

The subsequent developments associated with logic are more interdisciplinary. They include examples drawing on [[homotopy theory]] ([[classifying topos]]es). They involve links between category theory and mathematical logic, and also (as a high-level, organisational discussion) between category theory and theoretical computer science based on [[type theory]]. Granted the general view of [[Saunders Mac Lane]] about ''ubiquity'' of concepts, this gives them a definite status. The use of toposes as unifying bridges in mathematics has been pioneered by [[Olivia Caramello]] in her 2017 book.<ref>{{cite book|authorlink1=Olivia Caramello |last1=Caramello |first1=Olivia |title=Theories, Sites, Toposes: Relating and studying mathematical theories through topos-theoretic 'bridges |date=2017 |publisher=Oxford University Press |isbn=9780198758914 |doi=10.1093/oso/9780198758914.001.0001|url=https://oxford.universitypressscholarship.com/view/10.1093/oso/9780198758914.001.0001/oso-9780198758914}}</ref>