Let be an optional time as it was defined in (2.1.1). (a) Is the occurrence of

Let τ be an optional time as it was defined in (2.1.1).

(a) Is the occurrence of event {τ > t} completely determined by the values of the r.v.’s ξ₀, ..., ξ_t?

(b) Explain why P(τ ∞_t=0 P(τ = t).