Talk:Extension (model theory)

From Wikipedia, the free encyclopedia

[edit] substructure

The definition I've seen for a "A a substructure of B" stipulates only that the interpretation of relation symbols in A be contained in the restrictions of their interpretations in B, not that they be equal. I've changed the definition here accordingly. -- passerby 141.70.93.180 20:42, 3 December 2007 (UTC)

Do you know where you saw that? It certainly isn't common in model theory. I checked Marker (2002) just now, for example. — Carl (CBM · talk) 21:20, 3 December 2007 (UTC)

Hmm. My sources seem to agree with yours. (Don't know where I picked up that idea . . . .) I'll fix the page. -- passerby 141.70.93.180 11:01, 4 December 2007 (UTC)

That's a relief. You should consider getting a username,by the way. It's anonymous and free. — Carl (CBM · talk) 14:00, 4 December 2007 (UTC)