Libraries problem

Hi,
I bought an Arduino starter kit and I installed Arduino IDE on a debian 8 without problem.

I finished the sketches 1 to 4 and I made some tests, I learn how to use this card.

But, now, I need to compile the code of the fifth sketch, and I have a problem.

The error message is like the example. It is in french, but I translated it.

FileSketch05.ino:1.18:  fatal error: servo.h: Aucun fichier  ou dossier de ce type  (it is in french)
the translation of the message is "no files or folders of this type"

compilation terminated.

, arduino-core packet for debian 8 is installed

jonas@mobitux3:/$ sudo aptitude search arduino
i   arduino                                                    - EDI et bibliothèques pour carte d'expérimentation AVR                
i   arduino-core                                               - code, exemples et bibliothèques pour la plate-forme Arduino          
i   arduino-mighty-1284p                                       - Platform files for Arduino to run on ATmega1284P                     
i   arduino-mk                                                 - programmez votre Arduino depuis la ligne de commande                 
jonas@mobitux3:/$

I don't view where is the problem.

The source code is :

#include<servo.h>
Servo myServo;

//initialisation constante potar et variables valeur analogique et angle.
int const potarPin = A0 ;
int potarVal ;
int angle ;


void(setup)(
   myServo.attach(9);  //le servomoteur est relié à la pin 9 
   Serial.begin(9600);  //vitesse de transmission série 9600 bauds 
   )
 
 void(loop)(
    potarVal = analogRead(potarPin);
    Serial.print("La valeur potarVal est :  ");
    Serial.print(potarVal);
    angle = map(potarVal,0,1023,0,179);
    Serial.print(", la valeur angle est : ");
    Serial.println(angle);
    myServo.write(angle); // met le servomoteur a l'angle correspondant.
    delay(15);
    )

I hoped find packets of libraries on the arduino site, so I found manual, explaination, but I didn't find the packets.

Is somebody understand my problem ?
Could you help me ?

Thank-you

I am sorry...
I find the error...

The name of library is Servo.h, not servo.h.