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: For all x, if x reads a book, then x is a sailor. For all x, x is not a sailor. For all x, if x were a sailor, then x is reading a book. For all x, x will not climb a mountain or x will work. For all x, x will climb a mountain or x will read a book.
For all x, x will not read a book can be inferred via the universal modus tollens rule. For all x, x will read a book or x will work can be inferred via the universal resolution rule. For all x, x will read a book if and only if x is a sailor can be inferred via the universal biconditional introduction rule. For all x, x is a sailor if and only if x will read a book can be inferred via the universal biconditional introduction rule.