Let (Xn)n∈N be a (Fn)n∈N-supermartingale and assume (Xn)n∈N is bounded in L1 (i.e. supn∈NE[∣Xn∣]<∞). Then ∃l∈L1(Ω,F,P) such that Xn→l a.s. as n→∞.
Let (Xn)n∈N be (Fn)n∈N-martingale such that Xn≥0 ∀n∈N. Then ∃l∈L1(Ω,F,P) such that Xn→l a.s. as n→∞.