<<< mml $$2^{3^{4^5}}=2^{3^{4^{5^{\phantom{6}}}}}$$ >>> native [ ESuper (ENumber "2") (ESuper (ENumber "3") (ESuper (ENumber "4") (ENumber "5"))) , ESymbol Rel "=" , ESuper (ENumber "2") (ESuper (ENumber "3") (ESuper (ENumber "4") (ESuper (ENumber "5") (EPhantom (ENumber "6"))))) ]