Mathematical Notation in Notebooks
If you use the notebook front end for the Wolfram Language, then you can enter some of the operations discussed here in special ways.
multivariate partial derivative
This is one of the standard palettes for entering mathematical operations. When you click a button in the palette, the form shown in the button is inserted into your notebook, with the black square replaced by whatever you had selected in the notebook.
Esc sum Esc
Esc prod Esc
Esc int Esc
Esc dd Esc
special differential for use in integrals
Esc pd Esc
Ctrl+_ or Ctrl+-
move to the subscript position or lower limit of an integral
Ctrl+^ or Ctrl+6
move to the superscript position or upper limit of an integral
Ctrl + Shift + ,
move to the underscript position or lower limit of a sum or product
Ctrl+& or Ctrl+7
move to the overscript position or upper limit of a sum or product
Ctrl+% or Ctrl+5
switch between upper and lower positions
Ctrl + Space
return from upper or lower positions
You can enter an integral like this. Be sure to use the special differential entered as EscddEsc, not just an ordinary d:
When entering a sum, product or integral that has limits, you can create the first limit using the standard control sequences for subscripts, superscripts, underscripts, or overscripts. However, you must use Ctrl+% to create the second limit.