Truth Tables on Two Propositions

p

q

t

Ú

¬

p

®

q

«

Ù

Ø (pÙ q)

Å

Ø q

Ø (p® q)

Ø p

Ø (q® p)

Ø (pÚ q)

c

T

T

T

T

T

T

T

T

T

T

F

F

F

F

F

F

F

F

T

F

T

T

T

T

F

F

F

F

T

T

T

T

F

F

F

F

F

T

T

T

F

F

T

T

F

F

T

T

F

F

T

T

F

F

F

F

T

F

T

F

T

F

T

F

T

F

T

F

T

F

T

F

col. #

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

 

Are these 16 all the possible distinct operators on two propositions?

To answer this question we make a possibility tree. First recall that there are four rows in any truth table on two propositions, and each row can be one of only two values, T or F. Thus there are two distinct choices for the first row; for each of these choices there are two choices for a second row (22 = 4 possible combinations); for each of these there are two choices for a third row (22× 2 = 8); and then there are two choices for the fourth row. All together there are 24 = 16 possible combinations of T and F (truth tables) on two propositions.

Truth Tables on Two Propositions

     

p
+
q

q'
+
p

 

p'
+
q

 

pq
+
p'q'

pq

(pq)'

p
Å
q

q'

pq'

p'

p'q

(p+q)'

 

p

q

t

Ú

¬

p

®

q

«

Ù

Ø (pÙ q)

Å

Ø q

Ø (p® q)

Ø p

Ø (q® p)

Ø (pÚ q)

c

T

T

T

T

T

T

T

T

T

T

F

F

F

F

F

F

F

F

T

F

T

T

T

T

F

F

F

F

T

T

T

T

F

F

F

F

F

T

T

T

F

F

T

T

F

F

T

T

F

F

T

T

F

F

F

F

T

F

T

F

T

F

T

F

T

F

T

F

T

F

T

F

col. #

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16