Negation of $$(p \Rightarrow q) \Rightarrow(q \Rightarrow p)$$ is :

Among the statements

(S1) : $$(p \Rightarrow q) \vee((\sim p) \wedge q)$$ is a tautology

(S2) : $$(q \Rightarrow p) \Rightarrow((\sim p) \wedge q)$$ is a contradiction

Statement $$\mathrm{(P \Rightarrow Q) \wedge(R \Rightarrow Q)}$$ is logically equivalent to :

Which of the following statements is a tautology?