diff --git a/src/sage/rings/rational.pyx b/src/sage/rings/rational.pyx index b1acb90b174..5bff1754afb 100644 --- a/src/sage/rings/rational.pyx +++ b/src/sage/rings/rational.pyx @@ -3979,6 +3979,18 @@ cdef class Z_to_Q(Morphism): from sage.categories.sets_with_partial_maps import SetsWithPartialMaps return Q_to_Z(self._codomain.Hom(self.domain(), category=SetsWithPartialMaps())) + def is_surjective(self): + r""" + Return whether this morphism is surjective. + + EXAMPLES:: + + sage: QQ.coerce_map_from(ZZ).is_surjective() + False + + """ + return False + cdef class Q_to_Z(Map): r""" A morphism from `\QQ` to `\ZZ`.