This paper provides three characterizations of final functors between internal groupoids in an exact category (in the sense of Barr). In particular, it is proved that a functor between internal groupoids is final if and only if it is internally full and essentially surjective.
Keywords: exact category, internal groupoid, final functor, comprehensive factorization
2010 MSC: 18A22; 18A99; 18B40; 18D35
Theory and Applications of Categories, Vol. 33, 2018, No. 11, pp 265-275.