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: If Jessica writes a letter, then Patricia is curious. Patricia is cooking or Jessica is writing a letter. For all y, if y cooks, then y is curious. For all y, if y were curious, then y is cooking.
For all y, y will cook if and only if y is curious can be inferred via the universal biconditional introduction rule. For all y, y is curious if and only if y will cook can be inferred via the universal biconditional introduction rule.