Official solution
p
q
r
\[ \sim \] p
A =
p \[ \wedge \] q
B =
\[ \sim \] p \[ \vee \] r
C =
(A \[ \to \] B)
D =
(B \[ \to \] A)
C \[ \vee \] D
T
T
T
F
T
T
T
T
T
T
T
F
F
T
F
T
T
T
T
F
T
F
F
T
T
F
T
T
F
F
F
F
F
T
T
T
F
T
T
T
F
T
T
F
T
F
T
F
T
F
T
T
F
T
F
F
T
T
F
T
T
F
T
F
F
F
T
F
T
T
F
T
\[\therefore\] Given statement is a tautology.