<<< native
[ EIdentifier "c"
, ESymbol Rel "="
, EOver
    False
    (EOver
       False
       (EGrouped
          [ EUnder
              False
              (EUnder False (EIdentifier "a") (ESymbol TUnder "\9183"))
              (EText TextNormal "real")
          , ESymbol Bin "+"
          , EUnder
              False
              (EUnder
                 False
                 (EGrouped
                    [ EIdentifier "b" , EStyled TextNormal [ EIdentifier "i" ] ])
                 (ESymbol TUnder "\9183"))
              (EText TextNormal "imaginary")
          ])
       (ESymbol TOver "\9182"))
    (EText TextNormal "complex number")
]
>>> eqn
c = {{{a from \[u23DF]} from {roman "real"} + {{b roman {i}} from \[u23DF]} from {roman "imaginary"}} to \[u23DE]} to {roman "complex number"}