ROOT (token: short_text [lag_newlines/spaces] {pos_id})       
 ¦--expr: mtcar [0/0] {1}                                     
 ¦   ¦--expr: mtcar [0/1] {4}                                 
 ¦   ¦   °--SYMBOL: mtcar [0/0] {3}                           
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {5}                           
 ¦   ¦--expr: mutat [1/1] {6}                                 
 ¦   ¦   ¦--expr: mutat [0/0] {8}                             
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: mutat [0/0] {7}         
 ¦   ¦   ¦--'(': ( [0/4] {9}                                  
 ¦   ¦   ¦--SYMBOL_SUB: x [1/1] {10}                          
 ¦   ¦   ¦--EQ_SUB: = [0/1] {11}                              
 ¦   ¦   ¦--expr: 1 [0/2] {13}                                
 ¦   ¦   ¦   °--NUM_CONST: 1 [0/0] {12}                       
 ¦   ¦   °--')': ) [1/0] {14}                                 
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {15}                          
 ¦   °--expr: if (F [1/0] {16}                                
 ¦       ¦--IF: if [0/1] {17}                                 
 ¦       ¦--'(': ( [0/0] {18}                                 
 ¦       ¦--expr: FALSE [0/0] {20}                            
 ¦       ¦   °--NUM_CONST: FALSE [0/0] {19}                   
 ¦       ¦--')': ) [0/1] {21}                                 
 ¦       ¦--expr: {
    [0/1] {22}                           
 ¦       ¦   ¦--'{': { [0/4] {23}                             
 ¦       ¦   ¦--expr: mutat [1/2] {24}                        
 ¦       ¦   ¦   ¦--expr: mutat [0/0] {26}                    
 ¦       ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: mutat [0/0] {25}
 ¦       ¦   ¦   ¦--'(': ( [0/0] {27}                         
 ¦       ¦   ¦   ¦--expr: . [0/0] {29}                        
 ¦       ¦   ¦   ¦   °--SYMBOL: . [0/0] {28}                  
 ¦       ¦   ¦   ¦--',': , [0/1] {30}                         
 ¦       ¦   ¦   ¦--SYMBOL_SUB: count [0/1] {31}              
 ¦       ¦   ¦   ¦--EQ_SUB: = [0/1] {32}                      
 ¦       ¦   ¦   ¦--expr: 2 [0/0] {34}                        
 ¦       ¦   ¦   ¦   °--NUM_CONST: 2 [0/0] {33}               
 ¦       ¦   ¦   °--')': ) [0/0] {35}                         
 ¦       ¦   °--'}': } [1/0] {36}                             
 ¦       ¦--ELSE: else [0/1] {37}                             
 ¦       °--expr: . [0/0] {39}                                
 ¦           °--SYMBOL: . [0/0] {38}                          
 °--COMMENT: # add [2/0] {40}                                 
