> > In[7]:= Pi + E // N + 5 // N > > > Out[7]= (5. + N)[5.85987] > > Gees -- what in the heck does "(5. + N)[5.85987]" mean?
It means 5.+N applied to 5.85987. (In Mathematica f[x] is how you would express applying f to x). And here's why: In[8]:= a+b//c+d//e Out[8]= e[(c + d)[a + b]] So Pi + E // N + 5 // N = N((5+N)[Pi+E]]. Mathematica's rules tell it that N[f[g]] = N[f][N[g] and N[f+g]=N[f]+N[g] so N[(5+N)[Pi+E]] = (5.+N)[5.85987] It doesn't have a rule telling it how to simplify (f+g)[x], so it quits here. This is a good example of Mathematica's model of computation based based on simplification rules. Mathematica take an expression, sees if any simplification rules apply, and if so it does the simplification and repeats until the expression stops changing. Issues arise when more than one rule would apply, and Mathematica's idea of which one to use differs from what you would expect. Still it's pretty cool the way Mathematica's conceptual model unites computation and algebraic simplification. Of course theoretically this isn't surprising. What's cool is that it works as well as it does. Cheers, Peter --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://sage.math.washington.edu/sage/ and http://sage.scipy.org/sage/ -~----------~----~----~----~------~----~------~--~---
