Doesn't even violate your d(f,g)=d(f,x)/d(g,x):   
      
     d(integrate(f,g),g) = d(integrate(f*d(g,x),x),x)/d(g,x)   
      
                         = f*d(g,x)/d(g,x)   
      
                         = f   
      
   Am Dienstag, 23. Januar 2018 03:09:09 UTC+1 schrieb burs...@gmail.com:   
   > So you mean:   
   >   
   >   integrate sin(x) 2*x dx   
   >   
   > Then you can define:   
   >   
   >    integrate(f,g) = integrate(f*d(g,x),x)   
   >   
   > Am Dienstag, 23. Januar 2018 03:05:46 UTC+1 schrieb Dr Huang:   
   > > On Tuesday, 23 January 2018 12:59:07 UTC+11, burs...@gmail.com  wrote:   
   > > > Well I guess integrate(f,g) if g is not a variable   
   > > > must be integrate(f,x)*integrate(g,x)/x^2, right?   
   > > wrong!   
   > > integrate(sin(x),x^2)=integrate sin(x) d(x^2)   
   > > can your system do ?   
   > >   
   > > >   
   > > > Just joking ...   
   > > >   
   > > > Am Dienstag, 23. Januar 2018 02:52:07 UTC+1 schrieb Dr Huang:   
   > > > > integrate(sin(x),x^2)=?   
   > > > > can your system do ?   
   > > > >   
   > > > > reference math handbook   
   > > > > www.mathHandbook.com   
      
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