                /**  Special output form for Sum   **/
 
/*A: S.Wolfram */
/*S: California Institute of Technology */
/*D: July 1981 */
/*U: October 1985*/
/*   K McIsaac. Updated to give a more compact and aesthetic expression 
     output*/
 
<XPR
_Sum[Pr][[$expr,{$var,$start,$end}]] :: \
		Fmt[{{0,0},{2,0}},Fmt[{{1,0},{1,-1},{1,1}},PSig,\
		Fmt[,$var,"=",$start],$end],Fmt[,"(",$expr,")"]]
_Sum[Pr][[$expr,{$var,$start,$end,$inc}]] :: \
		Fmt[{{0,0},{2,0}},Fmt[{{1,0},{1,-1},{1,1}},PSig,\
      		Fmt[,$var,"=",$start,",",$inc],$end],Fmt[,"(",$expr,")"]]

/* Print summation sign at end of quotient line. This improves readability, 
   particularly for multiple summation*/
_Div[Pr][[Sum[$$b],$c]] :: Fmt[2,1/$c,Sum[$$b]]
_Div[Pr][[$$a Sum[$$b],$c]] :: Fmt[2,$$a/$c,Sum[$$b]]

/*E:
SMP 1.5.0
Mon Oct 21 16:07:33 1985


#I[1]::  <XSumPR

#I[2]::  <xs

	   $$a
#O[2]:   ' ---  Sum[$$b]
	   $c

#I[3]::  Sum[1+x^2/y^2,{x,0,Inf}]

	 Inf       2
	 ---      x
#O[3]:*  >   (1 + --)
	 ---       2
	 x=0      y

#I[4]::  a^x b Sum[1/i,{i,0,Inf,3}]/(x^3-y^3)

	   x      Inf
	  a  b    ---    1
#O[4]:*  -------  >     (-)
	  3    3  ---    i
	 x  - y   i=0,3

#I[5]::  a+x^2 Sum[x^2+y^2 Sum[1/i,{i,0,x}]/(x+y),{x,0,Inf}]/(a+b)

		    Inf 	x
	       2    ---    2    ---  1     2
#O[5]:*  a +  x     >   ( y     >   (-) + x )
	     -----  ---  -----  ---  i
	     a + b  x=0  x + y  i=0

#I[6]::  Sum[Sum[a^2+b^2,{a,0,Inf}]/(x+y+z),{b,0,Inf}]

	 Inf    	 Inf
	 ---      1      ---
#O[6]:*  >   (---------  >     2    2 )
	 ---  x + y + z  --- (a  + b )
	 b=0    	 a=0

#I[7]::  <end>
*/
/*B: Does not allways print the integrand in the most pleasing place
     (see last example)*/
