Complete Works of Lewis Carroll (184 page)

Hence proposed Conclusion is right.

  9.

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

Hence proposed Conclusion is right.

10.

All
m
′
are
x
′
; All
m
are
y
.
Some
y
are
x
′
.

Hence proposed Conclusion is right.

SL7-A
Solutions for § 7, Nos.
1–6.

1.

No doctors are enthusiastic;

You are enthusiastic.

    You are not a doctor.

Univ.
“persons”;
m
 = enthusiastic;
x
 = doctors;
y
 = you.

No
x
are
m
;

All
y
are
m
.

  All
y
are
x
′
.

∴
All
y
are
x
′
.

Hence proposed Conclusion is right.

2.

All dictionaries are useful;

Useful books are valuable.

    Dictionaries are valuable.

Univ.
“books”;
m
 = useful;
x
 = dictionaries;
y
 = valuable.

All
x
are
m
;

All
m
are
y
.

  All
x
are
y
.

∴
All
x
are
y
.

Hence proposed Conclusion is right.

3.

No misers are unselfish;

None but misers save egg-shells.

    No unselfish people save egg-shells.

Univ.
“people”;
m
 = misers;
x
 = selfish;
y
 = people who save egg-shells.

No
m
are
x
′
;

No
m
′
are
y
.

  No
x
′
are
y
.