<<< native [ EDelimited "(" ")" [ Right (EGrouped [ ESub (EIdentifier "a") (ENumber "1") , ESymbol Pun "," , ESub (EIdentifier "a") (ENumber "2") , ESymbol Pun "," , ESub (EIdentifier "a") (ENumber "3") ]) ] ] >>> eqn left ( {a sub 1 , a sub 2 , a sub 3} right )