Consider the following premises. For all x_15, x_15 is a carpenter and x_15 will write a letter. For all x_15, if x_15 were rich, then x_15 is not happy. For all x_15, if x_15 were a carpenter, then x_15 is playing squash. For all x_15, if x_15 climbs a mountain, then x_15 is rich. For all x_15, if x_15 plays squash, then x_15 is happy. Can we infer the following from them? There is at least one x_15 for which x_15 will climb a mountain.
 From the fact that for all x_15, x_15 is a carpenter and x_15 will write a letter we can infer that for all x_15, x_15 is a carpenter. From the fact that for all x_15, if x_15 were a carpenter, then x_15 is playing squash, and that for all x_15, if x_15 plays squash, then x_15 is happy we can infer that for all x_15, if x_15 were a carpenter, then x_15 is happy. From the fact that for all x_15, if x_15 were a carpenter, then x_15 is happy, and that for all x_15, x_15 is a carpenter we can infer that for all x_15, x_15 is happy. From the fact that for all x_15, if x_15 were rich, then x_15 is not happy, and that for all x_15, x_15 is happy we can infer that for all x_15, x_15 is not rich. Finally, from the fact that for all x_15, if x_15 climbs a mountain, then x_15 is rich, and that for all x_15, x_15 is not rich we can infer that for all x_15, x_15 will not climb a mountain, which contradicts that There is at least one x_15 for which x_15 will climb a mountain. Therefore, the answer is no.