[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is an organic phosphonate having O-1-carboxyvinyl and C-carboxy substituents. It is an organic phosphonate and a phosphonic ester. It is a conjugate acid of a 1-carboxylatovinyl carboxylatophosphonate(3-)."}, {"from": "gpt", "value": "[C][=C][Branch1][=Branch1][C][=Branch1][C][=O][O][O][P][=Branch1][C][=O][Branch1][=Branch1][C][=Branch1][C][=O][O][O]"}]