foo.c:4:1: error: unknown type name 'bool'
    4 | bool sushu(int n){if(n<=1)
      | ^~~~
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:5:9: error: 'false' undeclared (first use in this function)
    5 | {return false;}
      |         ^~~~~
foo.c:5:9: note: 'false' is defined in header '<stdbool.h>'; did you forget to '#include <stdbool.h>'?
foo.c:5:9: note: each undeclared identifier is reported only once for each function it appears in
foo.c:8:55: error: 'true' undeclared (first use in this function)
    8 |                                           else{return true;}
      |                                                       ^~~~
foo.c:8:55: note: 'true' is defined in header '<stdbool.h>'; did you forget to '#include <stdbool.h>'?
foo.c:10:34: warning: control reaches end of non-void function [-Wreturn-type]
   10 |                                  }
      |                                  ^

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