<<< native [ ESubsup (EIdentifier "A") (EIdentifier "B") (EIdentifier "C") , ESymbol Rel "=" , ESubsup (EIdentifier "A") (EIdentifier "B") (EIdentifier "C") , EPhantom (EFraction NormalFrac (EIdentifier "test") (EIdentifier "failed")) ] >>> eqn A sub B sup C = A sub B sup C hphantom {test over failed}