What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_1, if x_1 were a lawyer, then x_1 is listening to a song. For all x_1, if x_1 were happy, then x_1 is an electrician. For all x_1, if x_1 were an electrician, then x_1 is listening to a song. There is at least one x_1 for which x_1 is a lawyer or x_1 is happy.
For all x_1, if x_1 were happy, then x_1 is listening to a song.