- 5.5.3 f. on p. 215 -- give a printout from SYMLOG.

I don't remember if I said in class on 5 February whether you should give an "informal argument" to accompany the SD+ - derivation.

**Don't. Just do the SD+ - derivation.** - 5.5.3 h. Give a SYMLOG printout.
- 5.5.4 h. Give a SYMLOG printout.
- 5.5.5 b. Give a SYMLOG printout deriving both \alpha and
¬\alpha from the test set (\alpha being a wff of your choice).

Highlight the two lines where your two contradictory wffs appear. - 5.5.6 h. Give a SYMLOG printout.
**Also**give an informal English argument for (i.e., clearly and carefully explain in a few sentences) the validity of this argument. - 5.5.7 j. Give a SYMLOG printout.
- 5.6.6 b., e., f.

You must give reasons for your answers. I.e., as always, give a careful explanation if you say a certain*general*statement is true, and a single very specific counterexample if you say it is false. (Note that it may take some thought to rephrase the given statement in such a way that it is clearly either a general statement or a negation of a general statement.) You may use (and are encouraged to use) the**soundness**and**completeness**theorems.