Relatively Hyperimmune Relations on Structures

S. S. Goncharov, C. F. McCoy, J. F. Knight, V. S. Harizanov
2004 Algebra and Logic  
Let R be a relation on the domain of a computable structure A. We establish that the existence of an isomorphic copy B of A such that the image of R (¬R, resp.) is h-simple (h-immune, resp.) relative to B is equivalent to a syntactic condition, termed R is formally h-simple (formally h-immune, resp.) on A.
doi:10.1023/b:allo.0000020846.55332.2f fatcat:363ho5rpcveb3c5bww7f5qun3e