View Compilation Error

202395_0_17841.cpp: In function `int main()':
202395_0_17841.cpp:6: error: expected primary-expression before "double"
202395_0_17841.cpp:6: error: expected `;' before "double"
202395_0_17841.cpp:12: error: `a' undeclared (first use this function)
202395_0_17841.cpp:12: error: (Each undeclared identifier is reported only once for each function it appears in.)
202395_0_17841.cpp:14: error: `b' undeclared (first use this function)