If some obstetricians are not gynecologists, then some hematologists are radiologists. But it is not the case that there are any hematologists or gynecologists. Therefore, it is not the case that there are any obstetricians. (O, G, H, R)

Translate the following arguments into symbolic form. Then use the quantifier negation rule and the eighteen rules of inference to derive the conclusion of each. Do not use either conditional proof or indirect proof.