Consider the following premises. Jessica is playing a game if and only if Jennifer is an artist. For all x_23, if x_23 were an office clerk, then x_23 is a sailor. Mary is an office clerk or Elisabeth is cooking. If Elisabeth cooks, then Mary is a sailor. For all x_28, x_28 is not an artist. Can we infer the following from them? If we can, name the inference rule being used: Mary is not a sailor.
 From the fact that for all x_28, x_28 is not an artist we can infer that Jennifer is not an artist via universal instantiation. From the fact that for all x_23, if x_23 were an office clerk, then x_23 is a sailor we can infer that if Mary were an office clerk, then Mary is a sailor via universal instantiation. Finally, from the fact that if Mary were an office clerk, then Mary is a sailor, that if Elisabeth cooks, then Mary is a sailor, and that Mary is an office clerk or Elisabeth is cooking we can infer that Mary is a sailor via disjunction elimination, which contradicts that Mary is not a sailor. Therefore, the answer is no.