Lark exception with ProblemParser()

[lasmedina]

I'm trying to validate a string with a problem, using ProblemParser(). It's very similar to one of pddl's test cases. But I'm getting a lark exception every time.

  problem_str = dedent(
       """
   (define (problem hello-3-times)
       (:domain hello-world-functions)

       (:init
           ; if this was undefined, some planners would not assumed `0`
           (= (hello_counter jimmy) 0)
       )

       (:goal
           (> 5 3)
       )
   )
   """
   )
   ProblemParser()(problem_str)

I get the following errors

lark.exceptions.UnexpectedCharacters: No terminal matches '(' in the current parser context, at line 7 col 12

        (= (hello_counter jimmy) 0)
           ^
Expected one of: 
        * NAME

Previous tokens: Token('EQUAL_OP', '=')


During handling of the above exception, another exception occurred:

lark.exceptions.UnexpectedToken: Unexpected token Token('LPAR', '(') at line 7, column 12.
Expected one of: 
        * NAME
Previous tokens: [Token('EQUAL_OP', '=')]

What am I doing wrong?

[haz]

Seems to be failing to match here: https://github.com/AI-Planning/pddl/blob/main/pddl/parser/problem.lark#L19

@marcofavorito @francescofuggitti : Why is NAME an option for the basic_function_term?