["html",
  ["p",
    ["del",
      "this ",
      ["strong", "can"],
      " have ",
      ["em", "nested"],
      " markdown"
    ],
    " and ~this ",
    ["strong", "will"],
    " ",
    ["em", "not"],
    " have a line ",
    ["strong", "through"],
    " ~it"
  ]
]