texmath-0.13.1.2: test/roundtrip/msup-06.native

[ ESuper (EIdentifier "S") (ENumber "3")
, ESymbol Rel "="
, ESuper (EIdentifier "S") (ENumber "3")
, EPhantom
    (EFraction NormalFrac (EIdentifier "test") (EIdentifier "failed"))
]