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| operator:[Node content = = type = <class 'str'>]:2>0
| | item:[Node content = <identifier:a[<class 'str'>]> type = <class 'tokenizer.Token'>]:1>2
| | item:[Node content = list type = <class 'str'>]:3>2$!
| | | item:[Node content = <number:1[<class 'sympy.core.numbers.One'>]> type = <class 'tokenizer.Token'>]:4>3
| | | item:[Node content = <number:2[<class 'sympy.core.numbers.Integer'>]> type = <class 'tokenizer.Token'>]:5>3