refactoring: changed descriptions for 3 subtraction function

src/arithmeticSubtraction.c

@@ -2,21 +2,21 @@
 
 #include <stdlib.h>
 
-// arithmetic subtraction integer
+// arithmetic subtraction for integer
 int* subtraction_integer(int a, int b) {
     int* result= malloc(sizeof (int));
     *result=a - b;
     return result;
 }
 
-// arithmetic subtraction float
+// arithmetic subtraction for float
 float* subtraction_float(float a, float b) {
     float* result= malloc(sizeof (float));
     *result=a - b;
     return result;
 }
 
-// arithmetic subtraction double
+// arithmetic subtraction for double
 double* subtraction_double(double a, double b) {
     double* result= malloc(sizeof (double));
     *result=a - b;