SortedCovDsQ

SortedCovDsQ[expr]
returns True if the expr has all its covariant derivatives sorted, and False otherwise.
SortedCovDsQ[expr, cd]
only checks the covariant derivative cd.
  • Derivatives are sorted ascending with respect to postfix notation and descending with respect to prefix notation. Thus T_(ab;c;d)∇_d∇_cT_(ab) is sorted, whereas T_(ab;d;c)∇_c∇_dT_(ab) is unsorted.