I'm assuming that you don't bother to differentiate between upper and lower case, although in all forms of mathematics it makes a difference.
1. N -> R 2. O <-> R 3. (O -> R) -> L | (N -> O) & L 4. (R -> O) 2, Biconditional Elimination 5. (N -> O) 1, 4, Hypothetical Syllogism 6. (O -> R) 2, Biconditional Elimination 7. L 3, 6, Modus Ponens 8. :. (N -> O) & L 5, 7, Conjunction Introduction
John
My calculator said it, I believe it, that settles it
