A prompt can be designed to test a large language model's ability to handle nested structures by asking it to complete a sequence of brackets. The model must generate the correct closing brackets to ensure syntactic validity. For instance, a prompt might be: 'Complete the rest of the sequence, making sure that the parentheses are closed properly. Input: [ [' or a similar prompt with the input '[ ['. These prompts require the model to understand nesting and provide the corresponding closing brackets in the correct order.