Recent content by Soi-Arse

Homework Statement 1.Assume the language has equality and a two-place predicate symbol. Given two structures (N;<) and (R;<), find a sentence true in one structure and false in the other. Can these two structures be elementarily equivalent? Can they be isomorphic? Why or why not? 2.The...

How to write down the sentences saying that c and d are far apart? And what's the purpose to do so for showing that there is an elementarily equivalent structure B that is not connected. Actually this is a question from the logic textbook " A mathematical introduction to logic " by Herbert...