Consider the following premises. There is at least one y for which y is a taxi driver if and only if y will go running. For all y, if y were curious, then y is a taxi driver. For all y, if y were a taxi driver, then y is curious. For all y, y will not go running. Can we infer the following from them? For all y, y is curious.
 From the fact that there is at least one y for which y is a taxi driver if and only if y will go running, and that for all y, y will not go running we can infer that there is at least one y for which y is not a taxi driver. From the fact that for all y, if y were curious, then y is a taxi driver, and that for all y, if y were a taxi driver, then y is curious we can infer that for all y, y is curious if and only if y is a taxi driver. Finally, from the fact that for all y, y is curious if and only if y is a taxi driver, and that there is at least one y for which y is not a taxi driver we can infer that there is at least one y for which y is not curious, which contradicts that For all y, y is curious. Therefore, the answer is no.