On 6 December 2010 19:43, David Kirkby <[email protected]> wrote: > On 6 December 2010 19:33, Mike Hansen <[email protected]> wrote: >>> Here's the same sort of thing in Mathematica. >>> >>> In[3]:= 12 == 2 >>> >>> Out[3]= False >>> >>> In[4]:= 1 == 1 >>> >>> Out[4]= True >>> >>> In[5]:= AcrSin[x] == 2 ArcTan[x/(1+Sqrt[1+x^2])] >>> >>> x >>> Out[5]= AcrSin[x] == 2 ArcTan[----------------] >>> 2 >>> 1 + Sqrt[1 + x ] >>> >>> >>> In[7]:= x^3 == x x^2 >>> >>> Out[7]= True >>> >>> As you can see, when Mathematica does not know if the expression is >>> true or false, it returns the expression, not "True" or "False". >> >> Here's the same thing in Sage: >> >> sage: 12 == 2 >> False >> sage: 1 == 1 >> True >> sage: arcsin(x) == 2*arctan(x/(1+sqrt(1-x^2))) >> arcsin(x) == 2*arctan(x/(sqrt(-x^2 + 1) + 1)) >> sage: x^3 == x*x^2 >> x^3 == x^3 >> >> As you see, Sage does the exact same thing; although, it doesn't even >> try to determine if x^3 is equal x^3. But, the user is _explicitly_ >> asking to return either a True or False value -- that's what "bool" >> does in Python. >> >> --Mike > > Oh, I missed that - it is similar, but not identical to Mathematica's > TrueQ[]. Again, I personally prefer the MMA behavior. > > In[9]:= ?TrueQ > TrueQ[expr] yields True if expr is True, and yields False otherwise. > > In[10]:= True[ AcrSin[x] == 2 ArcTan[x/(1+Sqrt[1+x^2])]]
Oops, I put in "True" not "TrueQ" Mathematica then behaves the same as Sage In[1]:= TrueQ[AcrSin[x] == 2 ArcTan[x/(1+Sqrt[1+x^2])]] Dave -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
