If (p∧~q)∧(~q∧q) is
a contradiction
a tautology
neither a tautology nor a contradiction
both a tautology and a contradiction
If (p∧~q)∧(~p∧q)≡(p∧~p)∧(~q∧q) ≡(f∧f)≡f
(f→ false )
(By using associative laws and commutative laws)
∴(p∧~q)∧(~p∧q) is a contradiction.