A tree is a pair of a value and a list of trees. The "list of trees" part is what's constant about trees; the value is what makes it hard. What's a value? A na

A tree is a pair of a value and a list of trees. The "list of trees" part is what's constant about trees; the value is what makes it hard. What's a value? A name? A string? A text? Either a text, or a name and a map of strings to strings (simplified HTML)? A General Purpose Tree Editor would have to handle all those cases, and a whole lot more.