extract_model_formulation_system: |-
    offer description of the proposed model in this paper, write a latex formula with variable of the model. the format should be like "        "Model Name": {
                "description": "",
                "formulation": "",
                "variables": {
                    "\\hat{y}_u": "The predicted output for node u",
                }"
    such format content should be begin with ```json and end with ``` and the content should be in json format.