diff --git a/subjects/copy/README.md b/subjects/copy/README.md
index d35ad990..0b6f8c4a 100644
--- a/subjects/copy/README.md
+++ b/subjects/copy/README.md
@@ -2,17 +2,25 @@
 
 ### Instructions
 
-Your objective is to fix the program so that all functions work.
+Your objective is to fix the **functions** work so that the program works.
 
-- `nbr_function`, returns a tuple with the original value, the exponential and logarithm of that value
-- `str_function`, returns a tuple with the original value and the exponential of that value as a string
-- `vec_function`, returns a tuple with the original value and the logarithm of each value
+- `nbr_function` returns a tuple:
+	- with the `original` value
+	- the `exponential function` of the value
+	- and the `natural logarithm` of this `absolute` value
+- `str_function` returns a tuple:
+	- with the `original` value
+	- and the `exponential function` each value as a string (see the example)
+- `vec_function` returns a tuple:
+	- with the `original` value
+	- and the `natural logarithm` of each `absolute` value
 
-The objective is to now how ownership works with different types.
+The objective is to know how ownership works with different types.
 
 ### Notions
 
-- https://doc.rust-lang.org/rust-by-example/scope/move.html
+- [scope](https://doc.rust-lang.org/rust-by-example/scope/move.html)
+- [Primitive Type f64](https://doc.rust-lang.org/std/primitive.f64.html)
 
 ### Expected Functions
 
@@ -32,18 +40,21 @@ pub fn vec_function(b: Vec<u32>) -> (Vec<u32>, Vec<f64>) {
 Here is a possible program to test your function :
 
 ```rust
+use copy::*;
+
 fn main() {
-	let a = String::from("1 2 4 5 6");
-	let b = vec![1, 2, 4, 5];
-	let c: u32 = 0;
-
-	println!("{:?}", nbr_function(c));
-	// output: (12, 162754.79141900392, 2.4849066497880004)
-	println!("{:?}", vec_function(b));
-	// output: ([1, 2, 4], [0.0, 0.6931471805599453, 1.3862943611198906])
-	println!("{:?}", str_function(a));
-	// output: ("1 2 4", "2.718281828459045 7.38905609893065 54.598150033144236")
+    let a: u32 = 0;
+    let b = String::from("1 2 4 5 6");
+    let c = vec![1, 2, 4, 5];
+
+    println!("{:?}", nbr_function(a));
+    // output : (0, 1.0, inf)
+    println!("{:?}", str_function(b));
+    // output : ("1 2 4 5 6", "2.718281828459045 7.38905609893065 54.598150033144236 148.4131591025766 403.4287934927351")
+    println!("{:?}", vec_function(c));
+    //  output : ([1, 2, 4, 5], [0.0, 0.6931471805599453, 1.3862943611198906, 1.6094379124341003])
 }
+
 ```
 
 And its output:
@@ -51,7 +62,7 @@ And its output:
 ```console
 student@ubuntu:~/[[ROOT]]/test$ cargo run
 (0, 1.0, inf)
-([1, 2, 4, 5], [0.0, 0.6931471805599453, 1.3862943611198906, 1.6094379124341003])
 ("1 2 4 5 6", "2.718281828459045 7.38905609893065 54.598150033144236 148.4131591025766 403.4287934927351")
+([1, 2, 4, 5], [0.0, 0.6931471805599453, 1.3862943611198906, 1.6094379124341003])
 student@ubuntu:~/[[ROOT]]/test$
 ```