ROOT (token: short_text [lag_newlines/spaces] {pos_id})   
 ¦--expr: call( [0/0] {1}                                 
 ¦   ¦--expr: call [0/0] {3}                              
 ¦   ¦   °--SYMBOL_FUNCTION_CALL: call [0/0] {2}          
 ¦   ¦--'(': ( [0/0] {4}                                  
 ¦   ¦--expr: a [0/0] {6}                                 
 ¦   ¦   °--SYMBOL: a [0/0] {5}                           
 ¦   ¦--',': , [0/5] {7}                                  
 ¦   ¦--expr: b [1/5] {9}                                 
 ¦   ¦   °--SYMBOL: b [0/0] {8}                           
 ¦   ¦--',': , [1/1] {10}                                 
 ¦   ¦--expr: c [0/0] {12}                                
 ¦   ¦   °--SYMBOL: c [0/0] {11}                          
 ¦   °--')': ) [0/0] {13}                                 
 ¦--expr: call( [2/0] {14}                                
 ¦   ¦--expr: call [0/0] {16}                             
 ¦   ¦   °--SYMBOL_FUNCTION_CALL: call [0/0] {15}         
 ¦   ¦--'(': ( [0/0] {17}                                 
 ¦   ¦--expr: a [0/0] {19}                                
 ¦   ¦   °--SYMBOL: a [0/0] {18}                          
 ¦   ¦--',': , [0/1] {20}                                 
 ¦   ¦--expr: b [0/5] {22}                                
 ¦   ¦   °--SYMBOL: b [0/0] {21}                          
 ¦   ¦--',': , [1/5] {23}                                 
 ¦   ¦--expr: c [1/0] {25}                                
 ¦   ¦   °--SYMBOL: c [0/0] {24}                          
 ¦   °--')': ) [0/0] {26}                                 
 ¦--expr: call( [2/0] {27}                                
 ¦   ¦--expr: call [0/0] {29}                             
 ¦   ¦   °--SYMBOL_FUNCTION_CALL: call [0/0] {28}         
 ¦   ¦--'(': ( [0/0] {30}                                 
 ¦   ¦--expr: a [0/0] {32}                                
 ¦   ¦   °--SYMBOL: a [0/0] {31}                          
 ¦   ¦--',': , [0/0] {33}                                 
 ¦   °--')': ) [0/0] {34}                                 
 ¦--expr: call( [1/0] {35}                                
 ¦   ¦--expr: call [0/0] {37}                             
 ¦   ¦   °--SYMBOL_FUNCTION_CALL: call [0/0] {36}         
 ¦   ¦--'(': ( [0/0] {38}                                 
 ¦   ¦--expr: a [0/0] {40}                                
 ¦   ¦   °--SYMBOL: a [0/0] {39}                          
 ¦   ¦--',': , [0/0] {41}                                 
 ¦   °--')': ) [1/0] {42}                                 
 ¦--expr: call( [2/0] {43}                                
 ¦   ¦--expr: call [0/0] {45}                             
 ¦   ¦   °--SYMBOL_FUNCTION_CALL: call [0/0] {44}         
 ¦   ¦--'(': ( [0/0] {46}                                 
 ¦   ¦--expr: a [0/5] {48}                                
 ¦   ¦   °--SYMBOL: a [0/0] {47}                          
 ¦   ¦--',': , [1/0] {49}                                 
 ¦   °--')': ) [0/0] {50}                                 
 °--expr: mpg % [2/0] {51}                                
     ¦--expr: mpg [0/1] {53}                              
     ¦   °--SYMBOL: mpg [0/0] {52}                        
     ¦--SPECIAL-PIPE: %>% [0/4] {54}                      
     °--expr: summa [1/0] {55}                            
         ¦--expr: summa [0/0] {57}                        
         ¦   °--SYMBOL_FUNCTION_CALL: summa [0/0] {56}    
         ¦--'(': ( [0/0] {58}                             
         ¦--SYMBOL_SUB: avg_c [0/1] {59}                  
         ¦--EQ_SUB: = [0/1] {60}                          
         ¦--expr: mean( [0/0] {61}                        
         ¦   ¦--expr: mean [0/0] {63}                     
         ¦   ¦   °--SYMBOL_FUNCTION_CALL: mean [0/0] {62} 
         ¦   ¦--'(': ( [0/0] {64}                         
         ¦   ¦--expr: cty [0/0] {66}                      
         ¦   ¦   °--SYMBOL: cty [0/0] {65}                
         ¦   °--')': ) [0/0] {67}                         
         ¦--',': , [1/1] {68}                             
         ¦--SYMBOL_SUB: avg_h [0/1] {69}                  
         ¦--EQ_SUB: = [0/1] {70}                          
         ¦--expr: mean( [0/0] {71}                        
         ¦   ¦--expr: mean [0/0] {73}                     
         ¦   ¦   °--SYMBOL_FUNCTION_CALL: mean [0/0] {72} 
         ¦   ¦--'(': ( [0/0] {74}                         
         ¦   ¦--expr: hwy [0/0] {76}                      
         ¦   ¦   °--SYMBOL: hwy [0/0] {75}                
         ¦   °--')': ) [0/0] {77}                         
         ¦--',': , [1/1] {78}                             
         ¦--SYMBOL_SUB: n [0/1] {79}                      
         ¦--EQ_SUB: = [0/1] {80}                          
         ¦--expr: n() [0/0] {81}                          
         ¦   ¦--expr: n [0/0] {83}                        
         ¦   ¦   °--SYMBOL_FUNCTION_CALL: n [0/0] {82}    
         ¦   ¦--'(': ( [0/0] {84}                         
         ¦   °--')': ) [0/0] {85}                         
         ¦--',': , [1/1] {86}                             
         ¦--SYMBOL_SUB: n_cla [0/1] {87}                  
         ¦--EQ_SUB: = [0/1] {88}                          
         ¦--expr: n_dis [0/0] {89}                        
         ¦   ¦--expr: n_dis [0/0] {91}                    
         ¦   ¦   °--SYMBOL_FUNCTION_CALL: n_dis [0/0] {90}
         ¦   ¦--'(': ( [0/0] {92}                         
         ¦   ¦--expr: class [0/0] {94}                    
         ¦   ¦   °--SYMBOL: class [0/0] {93}              
         ¦   °--')': ) [0/0] {95}                         
         °--')': ) [0/0] {96}                             
