In regard to my question, isn't then choosing a mathematical proof for Lemmas, Theorems you need more a matter of taste than of necessity? Furthermore, who authorizes proofs to be true or usable and who controls the access rights?
I can tell you one nice story about Albertus Magnus and Thomas Aquinas. Both of them were catholic Saints, Albertus Magnus being the teacher of Thomas of Aquinas. There is one rumor, that once, Albertus Magnus built a machine that could answer every question that you asked to it correctly. He confronted Thomas of Aquinas with the machine and this one got very crazy because of this machine, because he could not understand, why this machine is in existence.
THE MIND is the machines that sets out to provide proof. Even a physical machine or program or software is set out to use for proof or verification, the origin begins with the mind to pre-program it with a set of rules of accepting or rejecting arguments.
THE MIND, PERSON AND THE MIND'S BY-PRODUCT: Can a product of the mind be separated from the min? Can the mind be separated from the person? Without the person the mind does not exists. Without the mind a product of the thinking process does not come into existence. Anything else that comes after the product are secondary. Person-mind-mind's by product seem inseparable.
VALIDITY OF LOGIC. The person's mind offers an argument. If the proposed argument is new or unfamiliar by the multitude or uncommon, a proof may be necessary to show its validity. in math and science, this has often been the case. Thus, an introduction of new new logic or idea is often presented as argument and followed by proof that what has been offered is valid.
If the argument comes with a condition that it should not be subject to proof, such an argument is taken out of the realm of objective test or verification and put unto a different category. The strength of this second type of argument depends on the people's choice and willingness to accept it. Many religious tenets fall into this second line.
Since it's a product of a mathematical mind, it' related to the provers soul, body, mind in the sense that the proof can be non-unique.
This relationship is time-dependent. But then it begins the abstract existence. Concerning proofs generated by a computer. Initially any computer is given an algorithm/software by a programmer, thus it is still related to a human mind via this link.
Its validity can be verified by the other experts.
@Stefan Gruner: ... 'hand-made' proofs in 'pure mathematics' differ considerably in their 'nature' from the kind of proofs produced by machines.
I would say that every proof of a theorem by a working mathematician is an instance of pure mathematics. Such proofs rely on a mathematician's understanding, knowledge and training that makes it possible to make connections between axioms, definitions and, possibly expressions to arrive at a conclusion that proves a theorem.
By contrast, a computer lacks the understanding of a mathematician. And a computer lacks the depth and richness of the semantics of the symbols known to every working mathematician, needed in writing down proofs of theorems. The mechanization of theorem-proving is interesting (HOL is an example):
Still we are human beings when we are mathematicians and computers are just dead objects. Doing pure mathematics could be a mental effort only developing alongside with any other skills like Yoga. Maybe even a mathematician could become holy as to preserve his skills into all his future lifes.
I like the story about Albertus Magnus and Thomas Acquinas: @Thomas Korimort: Albertus Magnus built a machine that could answer every question that you asked to it correctly. He confronted Thomas of Aquinas with the machine and this one got very crazy because of this machine, because he could not understand, why this machine is in existence.
Thomas of Acquinas (or simply Thomas Acquinas or just Acquinas) is well-known for his reverence for Aristotle ("The Philosopher"), and for his many interesting proofs, e.g., his 5 proofs of the existence of God in his Summa Theologica. It may be that Acquinas had trouble with existence proofs for the existence of thinking machines, especially, since, as far as I know, no machine is capable of independent reasoning about theorems. By independent, I mean without being programmed to answer questions or deduce a new proof of a theorem or, for that matter, to introduce a theorem that requires proof.
@James F Peters: There is even more ancient material on computing. The language of egyptian priesthood involved symbols on moving taking souls out of the bodies and putting in some body. That could have been a view on computing, that was more reconciled with the universe than our present day view on this topic. As transfer of souls could be interpreted as a kind of programming and library mechanism. Our present day view on computing still has not penetrated beyond considering simply machines as computing devices instead of considering this technology as a playground for learning the language of ancient (eqyptian) priesthood and also Aristotelian philosophy. It seems like our university education in mathematics and science needs to be supplemented with further life-long development and training in the field during the work life till death and beyond. I wonder whether university education could be to the point such that at the time of receiving a diploma all the learnt thing are already completely digested by the student.