foo.c:4:1: error: unknown type name 'bool'
    4 | bool sushu(int n){
      | ^~~~
foo.c:3:1: note: 'bool' is defined in header '<stdbool.h>'; did you forget to '#include <stdbool.h>'?
    2 | #include<math.h>
  +++ |+#include <stdbool.h>
    3 | 
foo.c: In function 'sushu':
foo.c:5:25: error: 'false' undeclared (first use in this function)
    5 |         if(n<=1){return false;}
      |                         ^~~~~
foo.c:5:25: note: 'false' is defined in header '<stdbool.h>'; did you forget to '#include <stdbool.h>'?
foo.c:5:25: note: each undeclared identifier is reported only once for each function it appears in
foo.c:7:16: error: 'true' undeclared (first use in this function)
    7 |         return true;
      |                ^~~~
foo.c:7:16: note: 'true' is defined in header '<stdbool.h>'; did you forget to '#include <stdbool.h>'?
foo.c:8:1: warning: control reaches end of non-void function [-Wreturn-type]
    8 | }
      | ^

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