The Meaning of Mono and EPI in Some Familiar Categories
W. D. Burgess · Canadian Mathematical Bulletin · 1965
This expository note was prompted by some questions asked by Professor P. Hilton during his lectures "Catégories non-abétiennes" at the University of Montréal, July 1964. The descriptions of set functions as one to one and as onto can be characterized in terms of set function composition. A set function is one to one iff it has the left cancellation property, that is, f · g = f · h implies g = h.