1. (10pts)

process p[i : 0..n-1]

inp  N     :  set {g| p[g] is a neighbor of p[i]}
var  ready :  boolean,  {init. true}
     j     :  N
par  g     :  N

begin
     ready -> ready, j := false, any;
              send rqst to p[j]
[]   rcv rply from p[j] -> ready := true
[]   rcv rqst from p[g] -> send rply to p[g]
end

2. (10pts)

process p
const  n
var    ready : array[0..n-1] of boolean  {init. true}
       i     : 0..n-1
par    j     : 0..n-1

begin
     ready[j] -> ready[j] := false; send rqst(j) to q
[]   rcv rply(i) from q -> ready[i] := true
[]   rcv error from q -> skip
[]   timeout ~ready[j] ^ rqst(j)#ch.p.q=0 ^ rply(j)#ch.q.p=0 ->
                                            ready[j] := true
end