<<< native
[ ESubsup (EIdentifier "D") (EIdentifier "x") (ENumber "2")
, ESymbol Rel "="
, ESubsup
    (EIdentifier "D")
    (EUnder False (EIdentifier "x") (EPhantom (ENumber "0")))
    (EOver False (ENumber "2") (EPhantom (ENumber "0")))
]
>>> eqn
D sub x sup 2 = D sub {x from {hphantom 0}} sup {2 to {hphantom 0}}