1 files changed, 7 insertions, 2 deletions
diff --git a/ratio.h b/ratio.h
index ff4015e..e273f7f 100644
--- a/ratio.h
+++ b/ratio.h
@@ -1,3 +1,6 @@
+#ifndef RATIO_H
+#define RATIO_H
+
 #include <stdbool.h>
 
 typedef struct {bool s; unsigned long long n; unsigned long long d;} rational;
@@ -27,6 +30,8 @@ rational power(rational,unsigned int);
 
 double to_double(rational);
 
-bool to_string(char*,rational r);
+int to_string(char*,rational r);
+
+int root_to_string(char*,rational r,unsigned int);
 
-bool root_to_string(char*,rational r,unsigned int);
+#endif