On 09/02/2018 09:47, Simon Brandhorst wrote:

Return whether the group was defined as a subgroup of a bigger group.

This description is very unclear anyway. See also #24535 for ambiguities concerning group comparisons. For me there are two relevant concepts 1) whether H is a subgroup of G, for example sage: G = PermutationGroup([ [4,3,2,1], [2,1,4,3] ]) sage: H = PermutationGroup([ [4,3,2,1] ]) sage: H.is_subgroup(G) True Here I did *not* defined H as a subgroup of G (so the above description does not apply). Note that in order for this comparison to make sense, G and H must be subgroups of a same ambient group (here SymmetricGroup(4)). But there is no such thing as an .ambient_group method. 2) whether G contains a subgroup isomorphic to H. In this situation no need to have a common ambient group I think that more generally discussing and fixing the semantic of group comparisons (and more generally algebraic structures) would be a good idea... and the behavior would ideally be coherent among all of Sage! Vincent -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.