A matrix A, finite or infinite, is image partition regular (over the set N of positive integers) if and only if, whenever N is finitely colored, there is a vector ~x of the appropriate size with entries in N such that all entries of A~x are the same color (or monochromatic). A large number of characterizations of finite matrices that are image partition regular are known. There is no known characterization of infinite image partition regular matrices, and the classes of infinite matrices that are known to be image partition regular have been rather limited; we present a list of those classes of which we are aware. Extending an idea of Patra and Ghosh, we produce several new classes of infinite image partition regular matrices.
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