ROOT (token: short_text [lag_newlines/spaces] {pos_id})
 ¦--expr:  [0/0] {1}                                   
 ¦   ¦--expr:  [0/0] {3}                               
 ¦   ¦   °--SYMBOL: a [0/0] {2}                        
 ¦   ¦--'~': ~ [0/0] {4}                               
 ¦   °--expr:  [0/0] {6}                               
 ¦       °--SYMBOL: b [0/0] {5}                        
 ¦--expr:  [1/0] {7}                                   
 ¦   ¦--'~': ~ [0/0] {8}                               
 ¦   °--expr:  [0/0] {10}                              
 ¦       °--SYMBOL: b [0/0] {9}                        
 ¦--expr:  [1/0] {11}                                  
 ¦   ¦--'~': ~ [0/0] {12}                              
 ¦   °--expr:  [0/0] {13}                              
 ¦       ¦--expr:  [0/0] {15}                          
 ¦       ¦   °--SYMBOL: b [0/0] {14}                   
 ¦       ¦--'+': + [0/1] {16}                          
 ¦       °--expr:  [0/0] {18}                          
 ¦           °--SYMBOL: c [0/0] {17}                   
 ¦--expr:  [1/0] {19}                                  
 ¦   ¦--expr:  [0/1] {20}                              
 ¦   ¦   ¦--expr:  [0/1] {22}                          
 ¦   ¦   ¦   °--SYMBOL: a [0/0] {21}                   
 ¦   ¦   ¦--'+': + [0/1] {23}                          
 ¦   ¦   °--expr:  [0/0] {25}                          
 ¦   ¦       °--SYMBOL: b [0/0] {24}                   
 ¦   ¦--'~': ~ [0/0] {26}                              
 ¦   °--expr:  [0/0] {28}                              
 ¦       °--SYMBOL: c [0/0] {27}                       
 ¦--expr:  [2/1] {29}                                  
 ¦   ¦--expr:  [0/2] {31}                              
 ¦   ¦   °--SYMBOL: a [0/0] {30}                       
 ¦   ¦--'~': ~ [0/0] {32}                              
 ¦   °--expr:  [0/0] {34}                              
 ¦       °--SYMBOL: b [0/0] {33}                       
 ¦--expr:  [1/0] {35}                                  
 ¦   ¦--'~': ~ [0/0] {36}                              
 ¦   °--expr:  [0/0] {38}                              
 ¦       °--SYMBOL: b [0/0] {37}                       
 ¦--expr:  [1/0] {39}                                  
 ¦   ¦--'~': ~ [0/2] {40}                              
 ¦   °--expr:  [0/0] {41}                              
 ¦       ¦--expr:  [0/0] {43}                          
 ¦       ¦   °--SYMBOL: b [0/0] {42}                   
 ¦       ¦--'+': + [0/0] {44}                          
 ¦       °--expr:  [0/0] {46}                          
 ¦           °--SYMBOL: c [0/0] {45}                   
 °--expr:  [1/0] {47}                                  
     ¦--expr:  [0/0] {48}                              
     ¦   ¦--expr:  [0/1] {50}                          
     ¦   ¦   °--SYMBOL: a [0/0] {49}                   
     ¦   ¦--'+': + [0/1] {51}                          
     ¦   °--expr:  [0/0] {53}                          
     ¦       °--SYMBOL: b [0/0] {52}                   
     ¦--'~': ~ [0/2] {54}                              
     °--expr:  [0/0] {56}                              
         °--SYMBOL: c [0/0] {55}                       
