Isomorphisms of models. (in logic).

[MathematicalPhysicist]

suppose our language contains one unary syombol function.
we are given the next 5 models:
A=<Z,x+1> B=<Z,x-1> C=<Q,-x> D=<Z,-x> E=<Q,x^2>
write which of the models are isomorphic to each other.
where Z is the integer set, and Q is the ratioanls set.

my answer is that: A isomorphic to B, and C isomorphic to D, and these are the only isomorphisms.

 

[lalbatros]

I don't understand your question, but I am curious.
Could you explain it, or could you give me a link where I could find the basic definitions to understand you questions.

Thanks,

Michel

 

[MathematicalPhysicist]

run a search on isomorphism of models in logic, and one of the things you'll find is this:
http://www.swif.uniba.it/lei/foldop/foldoc.cgi?isomorphism+of+models