Show that the consensus impossibility remains true when the CC-validity property (a decided value is a proposed value), is weakened as follows. • Weak CC-validity. There are executions in which 0 is...

Show that the consensus impossibility remains true when the CC-validity property (a decided

value is a proposed value), is weakened as follows.

• Weak CC-validity. There are executions in which 0 is decided and there are executions in

which 1 is decided.

Let us observe that this validity property does relate the output to the input. It does not prevent

the processes from deciding 0 when they all propose 1. It is a non-trivial property stating that

the same value cannot always be decided (which captures the non-deterministic dimension of

consensus).

Solution in [162].