View Compilation Error

0_0_24474291_7814.cpp: In function 'vi next()':
0_0_24474291_7814.cpp:32:1: error: 'P' was not declared in this scope
 P ++;
 ^
0_0_24474291_7814.cpp:37:8: error: 'f' was not declared in this scope
 } else f
        ^
0_0_24474291_7814.cpp:40:1: error: 'v' was not declared in this scope
 v[i] = to[i][*p - 'a'];
 ^
0_0_24474291_7814.cpp:42:8: error: 'v' was not declared in this scope
 return v;
        ^
0_0_24474291_7814.cpp: In function 'vi expr()':
0_0_24474291_7814.cpp:57:12: error: a function-definition is not allowed here before '{' token
 int main() {
            ^
0_0_24474291_7814.cpp:88:1: error: expected '}' at end of input
 }
 ^