on a journey should be left behind.

Univ. is "things"; m = useful on a journey; x = umbrellas; y = things
that should be left behind.

.---------------. .-------.
All x are m; |(O) | (O)| | | |
All m' are y. | .---|---. | |---|---|
| | (I) | | |(I)| |
|---|---|---|---| .-------.
| | | | |
| .---|---. | .'. Some x' are y.
|(I) | (O)|
.---------------.

i.e. Some things, that are not umbrellas, should be left behind on a
journey.

11. Audible music causes vibration in the air;
Inaudible music is not worth paying for.

Univ. is "music"; m = audible; x = music that causes vibration in the
air; y = worth paying for.

.---------------. .-------.
All m are x; |(O) | | | | |
All m' are y'. | .---|---. | |---|---|
| | (I) | | |(O)| |
|---|---|---|(I)| .-------.
| |(O)|(O)| |
| .---|---. | .'. No x' are y.
|(O) | |
.---------------.

i.e. No music is worth paying for, unless it causes vibration in the
air.

12. Some holidays are rainy;
Rainy days are tiresome.

Univ. is "days"; m = rainy; x = holidays; y = tiresome.

.---------------. .-------.
Some x are m; | | | |(I)| |
All m are y. | .---|---. | |---|---|
| |(I)|(O)| | | | |
|---|---|---|---| .-------.
| | |(O)| |
| .---|---. | .'. Some x are y.
| | |
.---------------.

i.e. Some holidays are tiresome.

_Solutions for Sec. 6, Nos. 1-10._ SL6-A

1.

Some x are m; No m are y'. Some x are y.

.---------------. .-------.
| | | |(I)| |
| .---|---. | |---|---|
| |(I)|(O)| | | | |
|---|---|---|---| .-------.
| | |(O)| |
| .---|---. | Hence proposed Conclusion is right.
| | |
.---------------.
pg142
2.

All x are m; No y are m'. No y are x'.

.---------------.
|(O) | (O)|
| .--