<<< mml $\left(a_1,a_2,a_3\right)$ >>> native [ EDelimited "(" ")" [ Right (EGrouped [ ESub (EIdentifier "a") (ENumber "1") , ESymbol Pun "," , ESub (EIdentifier "a") (ENumber "2") , ESymbol Pun "," , ESub (EIdentifier "a") (ENumber "3") ]) ] ]