Re: [fricas-devel] Group domains in FriCAS

2016-12-07 Thread Martin Baker
On 07/12/16 01:01, Waldek Hebisch wrote: About your proposal: note that notion of permutation group is closely related to notion of subgroup (and at categorical level with final object of a category). Finitely presented groups are related to quotients (and first object of a category). As a

Re: [fricas-devel] Group domains in FriCAS

2016-12-06 Thread Waldek Hebisch
Martin Baker wrote: > > My initial thoughts about group domains related to homotopy in FriCAS is > that there is a need for at least 4 group domains shown at each corner > of this square: > > PermutationGroup <-equivalent-> GroupPresentation >|if finite

Re: [fricas-devel] Group domains in FriCAS

2016-12-05 Thread Bill Page
On 5 December 2016 at 12:31, Bill Page wrote: > > The collection "subgroups of the symmetric group of S" do not form a > group, rather they ARE groups in-and-of themselves. To be a Group a > domain needs to export some multiplication operator * that acts on > members

Re: [fricas-devel] Group domains in FriCAS

2016-12-05 Thread Bill Page
On 5 December 2016 at 11:46, Martin Baker wrote: > My initial thoughts about group domains related to homotopy in FriCAS is > that there is a need for at least 4 group domains shown at each corner of > this square: > > PermutationGroup <-equivalent-> GroupPresentation

[fricas-devel] Group domains in FriCAS

2016-12-05 Thread Martin Baker
My initial thoughts about group domains related to homotopy in FriCAS is that there is a need for at least 4 group domains shown at each corner of this square: PermutationGroup <-equivalent-> GroupPresentation |if finite | |