diff --git a/eBook/exercises/chapter_4/count_characters.go b/eBook/exercises/chapter_4/count_characters.go
index 1fc0ce2..abc3258 100755
--- a/eBook/exercises/chapter_4/count_characters.go
+++ b/eBook/exercises/chapter_4/count_characters.go
@@ -1,22 +1,23 @@
-package main
-
-import (
-	"fmt"
-	"unicode/utf8"
-)
-
-func main() {
-	// count number of characters:
-	str1 := "asSASA ddd dsjkdsjs dk"
-	fmt.Printf("The number of bytes in string str1 is %d\n",len(str1))
-	fmt.Printf("The number of characters in string str1 is %d\n",utf8.RuneCountInString(str1))
-	str2 := "asSASA ddd dsjkdsjsこん dk"
-	fmt.Printf("The number of bytes in string str2 is %d\n",len(str2))
-	fmt.Printf("The number of characters in string str2 is %d",utf8.RuneCountInString(str2))
-}
-/* Output:
-The number of bytes in string str1 is 22
-The number of characters in string str1 is 22
-The number of bytes in string str2 is 28
-The number of characters in string str2 is 24
-*/
\ No newline at end of file
+package main
+
+import (
+	"fmt"
+	"unicode/utf8"
+)
+
+func main() {
+	// count number of characters:
+	str1 := "asSASA ddd dsjkdsjs dk"
+	fmt.Printf("The number of bytes in string str1 is %d\n", len(str1))
+	fmt.Printf("The number of characters in string str1 is %d\n", utf8.RuneCountInString(str1))
+	str2 := "asSASA ddd dsjkdsjsこん dk"
+	fmt.Printf("The number of bytes in string str2 is %d\n", len(str2))
+	fmt.Printf("The number of characters in string str2 is %d", utf8.RuneCountInString(str2))
+}
+
+/* Output:
+The number of bytes in string str1 is 22
+The number of characters in string str1 is 22
+The number of bytes in string str2 is 28
+The number of characters in string str2 is 24
+*/
diff --git a/eBook/exercises/chapter_4/divby0.go b/eBook/exercises/chapter_4/divby0.go
index 36cfe6c..5a87c36 100755
--- a/eBook/exercises/chapter_4/divby0.go
+++ b/eBook/exercises/chapter_4/divby0.go
@@ -1,8 +1,8 @@
-package main
-
-func main() {
-	a, b := 10, 0
-	c := a / b // panic: runtime error: integer divide by zero
-
-	print(c)
-}
+package main
+
+func main() {
+	a, b := 10, 0
+	c := a / b // panic: runtime error: integer divide by zero
+
+	print(c)
+}
diff --git a/eBook/exercises/chapter_4/function_calls_function.go b/eBook/exercises/chapter_4/function_calls_function.go
index 62711a4..315973a 100755
--- a/eBook/exercises/chapter_4/function_calls_function.go
+++ b/eBook/exercises/chapter_4/function_calls_function.go
@@ -1,18 +1,19 @@
-package main
-
-var a string  // global scope
-
-func main() {
-	a = "G"
-	print(a)
-	f1()
-}
-func f1() {
-	a := "O"   // new local variable a, only scoped within f1() !
-	print(a)
-	f2()
-}
-func f2() {
-	print(a)   // global variable is taken
-}
-// GOG
\ No newline at end of file
+package main
+
+var a string // global scope
+
+func main() {
+	a = "G"
+	print(a)
+	f1()
+}
+func f1() {
+	a := "O" // new local variable a, only scoped within f1() !
+	print(a)
+	f2()
+}
+func f2() {
+	print(a) // global variable is taken
+}
+
+// GOG
diff --git a/eBook/exercises/chapter_4/global_scope.go b/eBook/exercises/chapter_4/global_scope.go
index 080a295..6531ad1 100755
--- a/eBook/exercises/chapter_4/global_scope.go
+++ b/eBook/exercises/chapter_4/global_scope.go
@@ -1,19 +1,20 @@
-package main
-
-var a = "G" // global scope
-
-func main() {
-	n()
-	m()
-	n()
-}
-
-func n() {
-	print(a)
-}
-
-func m() {
-	a = "O" // simple assignment: global a gets a new value
-	print(a)
-}
-// GOO
\ No newline at end of file
+package main
+
+var a = "G" // global scope
+
+func main() {
+	n()
+	m()
+	n()
+}
+
+func n() {
+	print(a)
+}
+
+func m() {
+	a = "O" // simple assignment: global a gets a new value
+	print(a)
+}
+
+// GOO
diff --git a/eBook/exercises/chapter_4/local_scope.go b/eBook/exercises/chapter_4/local_scope.go
index 785bf7e..4db59be 100755
--- a/eBook/exercises/chapter_4/local_scope.go
+++ b/eBook/exercises/chapter_4/local_scope.go
@@ -1,17 +1,18 @@
-package main
-
-var a = "G"   // global (package) scope
-
-func main() {
-	n()
-	m()
-	n()
-}
-func n() {
-	print(a)
-}
-func m() {
-	a := "O"  // new local variable a is declared
-	print(a)
-}
-// GOG
\ No newline at end of file
+package main
+
+var a = "G" // global (package) scope
+
+func main() {
+	n()
+	m()
+	n()
+}
+func n() {
+	print(a)
+}
+func m() {
+	a := "O" // new local variable a is declared
+	print(a)
+}
+
+// GOG