Tom Boothby wrote: > On Mon, Aug 31, 2009 at 10:38 AM, Robert > Bradshaw<rober...@math.washington.edu> wrote:
>> As for the question at hand, I'm personally not convinced this is useful >> enough to merit another departure from pure Python. It also risks turning >> the valid Python expression "x!=120" into an invalid one (unless the rule > > bah. That's easy to get around. > >> is something like "! becomes factorial unless it's followed by one, but >> not two, equals signs...") And then people might expect "x!!" to be the >> double factorial instead of (x!)!. > > Agreed. If we were to implement this, we'd best look at other CAS's > and see how they treat these issues. > >> - Robert Em, I thought I'd try this in Mathematica In[1]:= 5! Out[1]= 120 In[2]:= 5!! Out[2]= 15 In[3]:= 5!!! Out[3]= 1307674368000 In[4]:= 5!!!! Out[4]= 2027025 In[5]:= 5!!!!! <spends a long time doing whatever it is trying to compute. > Anyone like to guess what it's doing? --~--~---------~--~----~------------~-------~--~----~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---