$4.$ Given four processes P$1$ to P$4$ and one each of six different resource types R$1$ to R$6,$ the following processes are currently allocated the following resources:

a$.$ P$1$: R$1,$ R$2$

b$.$ P$2$: R$3$

c$.$ P$3$: R$4,$ R$5$

d$.$ P$4$: R$6$

The following processes are requesting the following resources:

a$.$ P$1$: R$3$

b$.$ P$2$: R$1,$ R$4$

c$.$ P$3$: R$2$

d$.$ P$4$: R$5$

Is this deadlocked? Draw a graph to show your work.