<<< mml $$\underset{\mathrm{under\; script}}{\overset{\phantom{\mathrm{fail}}}{\mathrm{\_\; baseline\; \_}}}=\underset{\mathrm{under\; script}}{\mathrm{\_\; baseline\; \_}}$$ >>> native [ EUnderover False (EIdentifier "_ baseline _") (EIdentifier "under script") (EPhantom (EIdentifier "fail")) , ESymbol Rel "=" , EUnder False (EIdentifier "_ baseline _") (EIdentifier "under script") ]