Negation of the statement

"The payment will be made if and only if the work is finished in time." Is

Let $$\mathrm{p}, \mathrm{q}, \mathrm{r}$$ be three statements, then $$[p \rightarrow(q \rightarrow r)] \leftrightarrow[(p \wedge q) \rightarrow r]$$ is

If truth values of statements $$\mathrm{p}, \mathrm{q}$$ are true, and $$\mathrm{r}$$, $$s$$ are false, then the truth values of the following statement patterns are respectively

$$\begin{aligned} & \mathrm{a}: \sim(\mathrm{p} \wedge \sim \mathrm{r}) \vee(\sim \mathrm{q} \vee \mathrm{s}) \\ & \mathrm{b}:(\sim \mathrm{q} \wedge \sim \mathrm{r}) \leftrightarrow(\mathrm{p} \vee \mathrm{s}) \\ & \mathrm{c}:(\sim \mathrm{p} \vee \mathrm{q}) \rightarrow(\mathrm{r} \wedge \sim \mathrm{s}) \end{aligned}$$

The negation of the statement $$(p \wedge q) \rightarrow(\sim p \vee r)$$ is