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12:44 PM
In mathematical textbooks (for instance the Kelly's General Topology or the Spivak's Calculus) a theorem has hypotheses and a thesis.

In formal mathematics is different: A theorem of a formal theory L is a wff φ of L such that φ is the last wff of some proof in L. Such a proof is called a proof of φ in L.

However, in in formal mathematics there is something like hypotheses found in textbooks:

A wff φ is said to be a consequence, in a formal theory L, of a finite set $\Gamma$ of wffs if and only if there is a sequence $\beta_1,...,\beta_k$ of wffs such that φ is $\beta_k$ and, for each
 
1:00 PM
The last was answered in meta. I can not post it in math.stackexchange.com.
 
1:13 PM
@CarlosFreites: You can come to the logic chat-room if you like. On first glance it seems you want to do something like Fitch-style natural deduction (see posts linked from my profile for one flavour).
 
2:05 PM
Thank you! I will.
 

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