simplify {{1, -1, 2, 1}, {-2, 1, -3, 0}, {3, -1, -2, 3}, {1, 2,- 1,- 3}}.( inverse {{1, -1, 2, 1}, {-2, 1, -3, 0}, {3, -1, -2, 3}, {1, 2,- 1,- 3}})

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