texmath-0.13.2: test/writer/starmath/066_standalone_plus_minus_scripts_get_neutral_operands.test
<<< tex
r_{r,e}=r_{r,e}^{+}-r_{r,e}^{-}
>>> starmath
r_{{r, e}} = r_{{r, e}}^{{} + {}} - r_{{r, e}}^{{} - {}}
<<< tex
r_{r,e}=r_{r,e}^{+}-r_{r,e}^{-}
>>> starmath
r_{{r, e}} = r_{{r, e}}^{{} + {}} - r_{{r, e}}^{{} - {}}