arithmetic Subtraction specification

src/arithmeticSubtraction.c

@@ -14,6 +14,7 @@ float* subtraction_float(float a, float b) {
     *result=a - b;
     return result;
 }
+//arithmetic Subtraction specification double
 double* subtraction_double(double a, double b) {
     double* result= malloc(sizeof (double));
     *result=a - b;