Consider the following premises. For all x_13, x_13 is not a taxi driver. There is at least one x_13 for which x_13 is happy. For all x_13, x_13 is a taxi driver or x_13 will listen to a song. Can we infer the following from them? There is at least one x_13 for which x_13 is happy or x_13 is a mechanic.
 From the fact that for all x_13, x_13 is a taxi driver or x_13 will listen to a song, and that for all x_13, x_13 is not a taxi driver we can infer that for all x_13, x_13 will listen to a song. From the fact that there is at least one x_13 for which x_13 is happy, and that for all x_13, x_13 will listen to a song we can infer that there is at least one x_13 for which x_13 is happy and x_13 will listen to a song. From the fact that there is at least one x_13 for which x_13 is happy and x_13 will listen to a song we can infer that there is at least one x_13 for which x_13 is happy. Finally, from the fact that there is at least one x_13 for which x_13 is happy we can infer that there is at least one x_13 for which x_13 is happy or x_13 is a mechanic. Therefore, the answer is yes.