What is excluded from patenting?

The following are excluded from patenting:

a. Discoveries, scientific theories and mathematical methods.
b. Plans, principles and methods for intellectual activities, for play or for commercial activities, and computer programs such that they do not generate any technical effect beyond the normal interaction between software and PC (special conditions apply to computer programs, Ref. Can software be patented?).
c. Presentations of information.

Therapeutic and diagnostic methods are not patentable either, but this prohibition does not extend to products necessary for the implementation of these methods.