divergence.test

<<< native
[ ESymbol Ord "\8711"
, ESymbol Bin "\8901"
, EOver False (EIdentifier "v") (ESymbol Accent "\8407")
, ESymbol Rel "="
, EFraction
    NormalFrac
    (EGrouped
       [ ESymbol Ord "\8706" , ESub (EIdentifier "v") (EIdentifier "x") ])
    (EGrouped [ ESymbol Ord "\8706" , EIdentifier "x" ])
, ESymbol Bin "+"
, EFraction
    NormalFrac
    (EGrouped
       [ ESymbol Ord "\8706" , ESub (EIdentifier "v") (EIdentifier "y") ])
    (EGrouped [ ESymbol Ord "\8706" , EIdentifier "y" ])
, ESymbol Bin "+"
, EFraction
    NormalFrac
    (EGrouped
       [ ESymbol Ord "\8706" , ESub (EIdentifier "v") (EIdentifier "z") ])
    (EGrouped [ ESymbol Ord "\8706" , EIdentifier "z" ])
]
>>> starmath
nabla cdot vec v = {{partial v_x} over {partial x}} + {{partial v_y} over {partial y}} + {{partial v_z} over {partial z}}