Example E. g a can only speak Chinese, B can only speak spanish how can a communicate with B? a finds a translator c, who can speak chinese and English -B finds a translator d, who can speak spanish and English Two layers -Higher layer A and b -Lower layer: C and d11 Example • E.g., A can only speak Chinese, B can only speak Spanish, how can A communicate with B? —A finds a translator C, who can speak Chinese and English —B finds a translator D, who can speak Spanish and English • Two layers: —Higher layer: A and B —Lower layer: C and D