# Isomorphisms of models. (in logic).

Gold Member
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 eachother.
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.