Description: Define conjunction
(logical 'and'). Definition of [Margaris] p.
49. When
both the left and right operand are true, the result is true; when either
is false, the result is false. For example, it is true that (2 = 2
3 = 3). After we define the constant true (df-tru 1319) and the
constant false (df-fal 1320), we will be able to prove these truth
table values:  (truantru 1336),
 (truanfal 1337), 
(falantru 1338), and 
(falanfal 1339).
Contrast with
(df-or 359), (wi 4), (df-nan 1288),
and (df-xor 1305) . (Contributed by NM,
5-Aug-1993.) |