ROOT (token: short_text [lag_newlines/spaces] {pos_id})
 ¦--expr:  [0/0] {1}                                   
 ¦   ¦--expr:  [0/1] {3}                               
 ¦   ¦   °--SYMBOL: a [0/0] {2}                        
 ¦   ¦--LEFT_ASSIGN: <- [0/0] {4}                      
 ¦   ¦--COMMENT: # [0/2] {5}                           
 ¦   ¦--expr:  [1/1] {8}                               
 ¦   ¦   ¦--expr:  [0/0] {10}                          
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: b [0/0] {9}      
 ¦   ¦   ¦--'(': ( [0/0] {11}                          
 ¦   ¦   °--')': ) [0/0] {12}                          
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {13}                   
 ¦   ¦--expr:  [1/1] {14}                              
 ¦   ¦   ¦--expr:  [0/0] {16}                          
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: c [0/0] {15}     
 ¦   ¦   ¦--'(': ( [0/0] {17}                          
 ¦   ¦   °--')': ) [0/0] {18}                          
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {19}                   
 ¦   °--expr:  [1/0] {20}                              
 ¦       ¦--expr:  [0/0] {22}                          
 ¦       ¦   °--SYMBOL_FUNCTION_CALL: d [0/0] {21}     
 ¦       ¦--'(': ( [0/0] {23}                          
 ¦       °--')': ) [0/0] {24}                          
 ¦--expr:  [2/0] {25}                                  
 ¦   ¦--expr:  [0/1] {27}                              
 ¦   ¦   °--SYMBOL: a [0/0] {26}                       
 ¦   ¦--LEFT_ASSIGN: <- [0/1] {28}                     
 ¦   ¦--COMMENT: # [0/2] {29}                          
 ¦   ¦--expr:  [1/1] {32}                              
 ¦   ¦   ¦--expr:  [0/0] {34}                          
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: b [0/0] {33}     
 ¦   ¦   ¦--'(': ( [0/0] {35}                          
 ¦   ¦   °--')': ) [0/0] {36}                          
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {37}                   
 ¦   ¦--expr:  [1/1] {38}                              
 ¦   ¦   ¦--expr:  [0/0] {40}                          
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: c [0/0] {39}     
 ¦   ¦   ¦--'(': ( [0/0] {41}                          
 ¦   ¦   °--')': ) [0/0] {42}                          
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {43}                   
 ¦   °--expr:  [1/0] {44}                              
 ¦       ¦--expr:  [0/0] {46}                          
 ¦       ¦   °--SYMBOL_FUNCTION_CALL: d [0/0] {45}     
 ¦       ¦--'(': ( [0/0] {47}                          
 ¦       °--')': ) [0/0] {48}                          
 ¦--expr:  [3/0] {49}                                  
 ¦   ¦--expr:  [0/1] {51}                              
 ¦   ¦   °--SYMBOL: a [0/0] {50}                       
 ¦   ¦--LEFT_ASSIGN: <- [0/2] {52}                     
 ¦   ¦--expr:  [1/1] {55}                              
 ¦   ¦   ¦--expr:  [0/0] {57}                          
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: b [0/0] {56}     
 ¦   ¦   ¦--'(': ( [0/0] {58}                          
 ¦   ¦   °--')': ) [0/0] {59}                          
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {60}                   
 ¦   ¦--expr:  [1/1] {61}                              
 ¦   ¦   ¦--expr:  [0/0] {63}                          
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: c [0/0] {62}     
 ¦   ¦   ¦--'(': ( [0/0] {64}                          
 ¦   ¦   °--')': ) [0/0] {65}                          
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {66}                   
 ¦   °--expr:  [1/0] {67}                              
 ¦       ¦--expr:  [0/0] {69}                          
 ¦       ¦   °--SYMBOL_FUNCTION_CALL: d [0/0] {68}     
 ¦       ¦--'(': ( [0/0] {70}                          
 ¦       °--')': ) [0/0] {71}                          
 ¦--expr:  [2/0] {72}                                  
 ¦   ¦--expr:  [0/1] {74}                              
 ¦   ¦   °--SYMBOL: a [0/0] {73}                       
 ¦   ¦--LEFT_ASSIGN: <- [0/1] {75}                     
 ¦   ¦--expr:  [0/1] {80}                              
 ¦   ¦   °--SYMBOL: c [0/0] {79}                       
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {81}                   
 ¦   ¦--expr:  [1/0] {82}                              
 ¦   ¦   ¦--expr:  [0/0] {84}                          
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: b [0/0] {83}     
 ¦   ¦   ¦--'(': ( [0/0] {85}                          
 ¦   ¦   °--')': ) [0/0] {86}                          
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {87}                   
 ¦   ¦--expr:  [1/1] {88}                              
 ¦   ¦   ¦--expr:  [0/0] {90}                          
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: c [0/0] {89}     
 ¦   ¦   ¦--'(': ( [0/1] {91}                          
 ¦   ¦   °--')': ) [0/0] {92}                          
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {93}                   
 ¦   °--expr:  [1/0] {94}                              
 ¦       ¦--expr:  [0/0] {96}                          
 ¦       ¦   °--SYMBOL_FUNCTION_CALL: d [0/0] {95}     
 ¦       ¦--'(': ( [0/0] {97}                          
 ¦       °--')': ) [0/0] {98}                          
 ¦--expr:  [2/0] {99}                                  
 ¦   ¦--expr:  [0/1] {101}                             
 ¦   ¦   °--SYMBOL: a [0/0] {100}                      
 ¦   ¦--LEFT_ASSIGN: <- [0/2] {102}                    
 ¦   ¦--expr:  [1/1] {105}                             
 ¦   ¦   ¦--expr:  [0/0] {107}                         
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: b [0/0] {106}    
 ¦   ¦   ¦--'(': ( [0/0] {108}                         
 ¦   ¦   °--')': ) [0/0] {109}                         
 ¦   ¦--SPECIAL-PIPE: %>% [0/1] {110}                  
 ¦   ¦--COMMENT: # [0/2] {111}                         
 ¦   ¦--expr:  [1/1] {112}                             
 ¦   ¦   ¦--expr:  [0/0] {114}                         
 ¦   ¦   ¦   °--SYMBOL_FUNCTION_CALL: c [0/0] {113}    
 ¦   ¦   ¦--'(': ( [0/0] {115}                         
 ¦   ¦   °--')': ) [0/0] {116}                         
 ¦   ¦--SPECIAL-PIPE: %>% [0/2] {117}                  
 ¦   °--expr:  [1/0] {118}                             
 ¦       ¦--expr:  [0/0] {120}                         
 ¦       ¦   °--SYMBOL_FUNCTION_CALL: d [0/0] {119}    
 ¦       ¦--'(': ( [0/0] {121}                         
 ¦       °--')': ) [0/0] {122}                         
 °--COMMENT: # d [0/0] {123}                           
