PD+ Derivations

Fill in the following derivation. You may use any rule from SD+ or PD+.

*Shortcuts*:

- To type a universal quantifier, e.g., (^x), or an existential quantifier, like (%y), you can leave out the parentheses. They will be added in after you've moved on to the next field.
- You may use the
**standard typing shortcuts**, i.e., you need*not*use the shift key to get the computer to know you mean '&', '(', etc. **Slash shortcuts**: For all rules of inference of*SL*you may type the justification, TAB, then**type '/' or '//'**and TAB. The answer you intended will likely appear! This will*not work for PL rules*: we need to learn to do these on our own.**You may do more than one problem on this page**At any time you would like to start a new problem and give it a name just type "new" into the justification field. You'll be prompted for the rest.**.**

(As always, if you have questions, send me an e-mail at halpin@oakland.edu or use the course discussion forum.)