5.2d
Derivations with a Little Strategy

1. These problems look a little involved. But you should try to break complicated premises down by using rule like &E and MP. Often MT or DS can be helpful too at breaking down complicated sentences.

2. Remember that to use MP you need two inputs. One should be a conditional (= main connective horseshoe) and the other should be the antecedent ( = what comes before the horseshoe).

3. Also, try to think stategically: look at the goal and see how your derivation will end. Check the hints for help on this.

4. Selected answers are available...this time I selected all five!

5. Key Phrase = "&E"



Justification:       Sentence: