37      Thus, the object of protection under Directive 91/250 includes the forms of expression of a computer program and the preparatory design work capable of leading, respectively, to the reproduction or the subsequent creation of such a program (Bezpečnostní softwarová asociace, paragraph 37).

39      On the basis of those considerations, it must be stated that, with regard to the elements of a computer program which are the subject of Questions 1 to 5, neither the functionality of a computer program nor the programming language and the format of data files used in a computer program in order to exploit certain of its functions constitute a form of expression of that program for the purposes of Article 1(2) of Directive 91/250.

40      As the Advocate General states in point 57 of his Opinion, to accept that the functionality of a computer program can be protected by copyright would amount to making it possible to monopolise ideas, to the detriment of technological progress and industrial development.

42      With respect to the programming language and the format of data files used in a computer program to interpret and execute application programs written by users and to read and write data in a specific format of data files, these are elements of that program by means of which users exploit certain functions of that program.

43      In that context, it should be made clear that, if a third party were to procure the part of the source code or the object code relating to the programming language or to the format of data files used in a computer program, and if that party were to create, with the aid of that code, similar elements [sic!] in its own computer program, that conduct would be liable to constitute partial reproduction within the meaning of Article 4(a) of Directive 91/250.

44      As is, however, apparent from the order for reference, WPL did not have access to the source code of SAS Institute’s program and did not carry out any decompilation of the object code of that program. By means of observing, studying and testing the behaviour of SAS Institute’s program, WPL reproduced the functionality of that program by using the same programming language and the same format of data files.

45      The Court also points out that the finding made in paragraph 39 of the present judgment cannot affect the possibility that the SAS language and the format of SAS Institute’s data files might be protected, as works, by copyright under Directive 2001/29 if they are their author’s own intellectual creation (see Bezpečnostní softwarová asociace, paragraphs 44 to 46).

50      The Court observes that, from the wording of that provision, it is clear, first, that a licensee is entitled to observe, study or test the functioning of a computer program in order to determine the ideas and principles which underlie any element of the program.

51      In this respect, Article 5(3) of Directive 91/250 seeks to ensure that the ideas and principles which underlie any element of a computer program are not protected by the owner of the copyright by means of a licensing agreement.

52      That provision is therefore consistent with the basic principle laid down in Article 1(2) of Directive 91/250, pursuant to which protection in accordance with that directive applies to the expression in any form of a computer program and ideas and principles which underlie any element of a computer program are not protected by copyright under that directive.

53      Article 9(1) of Directive 91/250 adds, moreover, that any contractual provisions contrary to the exceptions provided for in Article 5(2) and (3) of that directive are null and void.

59      Consequently, the owner of the copyright in a computer program may not prevent, by relying on the licensing agreement, the person who has obtained that licence from determining the ideas and principles which underlie all the elements of that program in the case where that person carries out acts which that licence permits him to perform and the acts of loading and running necessary for the use of the computer program, and on condition that that person does not infringe the exclusive rights of the owner in that program.

60      As regards that latter condition, Article 6(2)(c) of Directive 91/250 relating to decompilation states that decompilation does not permit the information obtained through its application to be used for the development, production or marketing of a computer program substantially similar in its expression, or for any other act which infringes copyright.

61      It must therefore be held that the copyright in a computer program cannot be infringed where, as in the present case, the lawful acquirer of the licence did not have access to the source code of the computer program to which that licence relates, but merely studied, observed and tested that program in order to reproduce its functionality in a second program.

65      The Court has already held that the various parts of a work enjoy protection under Article 2(a) of Directive 2001/29, provided that they contain some of the elements which are the expression of the intellectual creation of the author of the work (Case C‑5/08 Infopaq International [2009] ECR I‑6569, paragraph 39).

66      In the present case, the keywords, syntax, commands and combinations of commands, options, defaults and iterations consist of words, figures or mathematical concepts which, considered in isolation, are not, as such, an intellectual creation of the author of the computer program.

67      It is only through the choice, sequence and combination of those words, figures or mathematical concepts that the author may express his creativity in an original manner and achieve a result, namely the user manual for the computer program, which is an intellectual creation (see, to that effect, Infopaq International, paragraph 45).

68      It is for the national court to ascertain whether the reproduction of those elements constitutes the reproduction of the expression of the intellectual creation of the author of the user manual for the computer program at issue in the main proceedings.

69      In this respect, the examination, in the light of Directive 2001/29, of the reproduction of those elements of the user manual for a computer program must be the same with respect to the creation of the user manual for a second program as it is with respect to the creation of that second program.