> Here is my video ...

It was very interesting, thanks. For me the highlight of the video was the 
"proving bottom-up" dialog, which can search for proofs of large depth 
automatically. Metamath.exe also has one (the "improve" command), and mmj2 
doesn't, as far as I'm aware, so in a sense metamath-lamp has partly 
surpassed mmj2 in functionality.

There was an interesting part near the end where the proof search couldn't 
figure out that A e. CC is implied by A e. RR, since the latter statement 
has the same length and hence isn't picked up by the "Less" search 
heuristic. I think mmj2's transformation script 
<https://github.com/digama0/mmj2/blob/master/mmj2jar/macros/transformations.js> 
can circumvent such issues in special cases, so there's potential for 
improving the search maybe by adding special tactics for set.mm which 
narrow down the search with specific theorems banned/allowed.

> I proved the fifth theorem. Again, apparently one hypothesis is not 
needed, the set B is not required to be not empty.

Nice! You shouldn't require nonemptyness until lemma 7, which postulates 
the existence of unity. I think it's a bit unfortunate that we allow empty 
magmas, since algebraic structures are usually assumed to be based on 
nonempty sets; this makes the theory more uniform.

-- 
You received this message because you are subscribed to the Google Groups 
"Metamath" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion visit 
https://groups.google.com/d/msgid/metamath/25756eb2-285c-4c49-8b07-ca9be49a3477n%40googlegroups.com.

Reply via email to