lower_free_indices
Make all free indices in an expression subscripts.
Free indicies (indices declared with the Indices(position=free)
property) can appear as subscripts or superscripts,
but sometimes it is useful to move them all into the same position. {a,b,c}::Indices(name=A, position=free);
{m,n,p}::Indices(name=B, position=fixed);
ex:=A_{a b m} B^{a b m};
\(\displaystyle{}\text{Attached property Indices(position=free) to }\left[a, b, c\right].\)
\(\displaystyle{}\text{Attached property Indices(position=fixed) to }\left[m, n, p\right].\)
\(\displaystyle{}A_{a b m} B^{a b m}\)
A_{a b m} B^{a b m}
lower_free_indices(_);
\(\displaystyle{}A_{a b m} B_{a b}\,^{m}\)
A_{a b m} B_{a b}^{m}
The opposite of this is
raise_free_indices
, which moves all indices to be superscripts.