/// is there an insertion at the given pos ?
bool isInserted(pos_type pos) const;
/// is there a deletion at the given pos ?
bool isDeleted(pos_type pos) const;
/// is the whole paragraph deleted ?
/// is there an insertion at the given pos ?
bool isInserted(pos_type pos) const;
/// is there a deletion at the given pos ?
bool isDeleted(pos_type pos) const;
/// is the whole paragraph deleted ?