View Compilation Error

0_0_18658836_25961.c:4:1: error: unknown type name 'bool'
 bool Is_prim(int x)  
 ^
0_0_18658836_25961.c: In function 'Is_prim':
0_0_18658836_25961.c:6:21: error: 'false' undeclared (first use in this function)
     if(x==1) return false;  
                     ^
0_0_18658836_25961.c:6:21: note: each undeclared identifier is reported only once for each function it appears in
0_0_18658836_25961.c:14:12: error: 'true' undeclared (first use in this function)
     return true;  
            ^