摘要
Let t（t<sub>1</sub>, t<sub>2</sub>）be a point on the plane, denote the Borel σ-algebra in R<sub>+</sub><sup>2</sup>={t: t<sub>1</sub>≥0, t<sub>2</sub>≥0}, ξ={ξ,（ω）, t∈R<sub>+</sub><sup>2</sup>}, real valued stochastic process on some probability space （Ω, P）. We say t（t<sub>1</sub>, t<sub>2</sub>）≥s（s<sub>1</sub>, s<sub>2</sub>） if t<sub>i</sub>≥s<sub>i</sub>, i=1, 2. R<sub>1</sub>=（s:s<sub>1</sub>≤t<sub>1</sub> or s<sub>2</sub>≤t<sub>2</sub>） =σ{ξ<sub>s</sub>,
基金
Project supported by the National Natural Science Foundation of China
