I would like to make a subscript with MaTeX that is in the bottom left hand corner instead of in the bottom right hand corner. Is there a way to do this. I looked in the documentation for Subscript but couldn't find a function to write a subscript in the left-hand corner. I want to write something like xP with the x as a subscript as a symbol for the number of n-permutations from an x-set. I know I can use Ctrl+& for over bar and Ctrl+Shift+& for underbar and Ctrl+_ for subscript and Ctrl +^ for Superscript and Ctrl+^ then % to shift to the subscript box or vice versa but I'm not sure how to add a left subscript. I'm also curious how to add an upper left subscript. These positions are often used for writing isotopes like 12C with the 12 as an upper left superscript. I found a way to add for example 12 6 C as:

\!\(
TagBox[
StyleBox[
RowBox[{"Grid", "[", 
RowBox[{
RowBox[{"List", "[", 
RowBox[{
RowBox[{"List", "[", 
RowBox[{
RowBox[{"Style", "[", 
RowBox[{"\"\<12\>\"", ",", "Smaller"}], "]"}], ",", "\"\<C\>\""}], 
         "]"}], ",", 
RowBox[{"List", "[", 
RowBox[{
RowBox[{"Style", "[", 
RowBox[{"\"\<6\>\"", ",", "Smaller"}], "]"}], ",", "SpanFromAbove"}], 
         "]"}]}], "]"}], ",", 
RowBox[{"Rule", "[", 
RowBox[{"Alignment", ",", 
RowBox[{"List", "[", 
RowBox[{
RowBox[{"List", "[", 
RowBox[{"Right", ",", "Center"}], "]"}], ",", 
RowBox[{"List", "[", "Center", "]"}]}], "]"}]}], "]"}], ",", 
RowBox[{"Rule", "[", 
RowBox[{"Spacings", ",", 
RowBox[{"List", "[", 
RowBox[{"0", ",", "0"}], "]"}]}], "]"}]}], "]"}],
ShowSpecialCharacters->False,
ShowStringCharacters->True,
NumberMarks->True],
FullForm]\)

Is there a less verbose way to do this? I figured it out with

Grid[{{Null, P}, {Style[x, Smaller], 
      SpanFromAbove}}, Alignment -> {{Right, Center}, {Center}}, 
  Spacings -> {0, 0}]

I just figured out a simple way to do it! The Classroom Assistant Palette has the left subscript and superscript! This is much more helpful instead of using complex combinations of Grid and Spacing. The entry is under Typesetting.