?start: document

document.0: box

string.0: (WS | TEXT | NEWLINE)+ 

text_box.0: string


ud_box.0: (ud_box_content | box) expand_content

u_box.0: u_box_content expand_content


u_box_content.0:  /[ \n]?\/u[ \n]?/  box /[ \n]?u\/[ \n]?/ 

ud_box_content.0: /\/ud[ \n]?/ box /[ \n]?ud\/[ \n]?/

expand_content.0: "(" box ")"


explainable_text_box.0:(ud_box|u_box|string)  (ud_box|u_box) (ud_box|string|u_box)*
    |(ud_box|u_box) (ud_box|u_box|string) (ud_box|string|u_box)*

            

?box.0: text_box                 
     | ud_box           
     |explainable_text_box  
       

WS: /[\t ]+/
TEXT: /[^ \/\(\)\n]+/
NEWLINE: /\n/

document
  |-ud_box
    |-text_box
      |-string
        |- j
        |-
|-expand_content
  |-text_box
     |-string
        |-a

document
|-explainable_text_box
  |-string
    |-j
  |-ud_box
    |-text_box
      |-string
        |-
    |-expand_content
      |-text_box
         |-string
          |-a