Andrée Charles Ehresmann (née Bastiani) is a category theorist. She is editor in chief of the journal Cahiers de Topologie et Géométrie Différentielle Catégoriques, founded by her late husband Charles Ehresmann. Andrée Ehresmann’s early papers were published under her maiden name Andrée Bastiani, and during a transition period under the hyphenated surname Bastiani-Ehresmann. On internalization of mathematical structures via sketches: