What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: Patricia is not listening to a song. Patricia is playing squash if and only if Sarah is an electrician. Linda is reading a book. For all z_3, z_3 will play squash if and only if z_3 will listen to a song.
Patricia is not listening to a song and Linda is reading a book can be inferred via the conjunction rule. Linda is reading a book and Patricia is not listening to a song can be inferred via the conjunction rule. If Patricia plays squash, then Sarah is an electrician can be inferred via the biconditional elimination rule. If Sarah were an electrician, then Patricia is playing squash can be inferred via the biconditional elimination rule. For all z_3, if z_3 plays squash, then z_3 is listening to a song can be inferred via the universal biconditional elimination rule. For all z_3, if z_3 listens to a song, then z_3 is playing squash can be inferred via the universal biconditional elimination rule.