A system has five processes P1 through P5 and four resource types R1 through R4.

There are 2 units of each resource type. Given that:

P1 holds 1 unit of R1 and requests 1 unit of R4

P2 holds 1 unit of R3 and requests 1 unit of R2

P3 holds one unit of R2 and requests 1 unit of R3

P4 requests 1 unit of R4

P5 holds one unit of R3 and 1 unit of R2, and requests 1 unit of R3

Show the resource graph for this state of the system.

Is the system in deadlock, and if so, which processes are involved?