@techreport{jl_2007/operator_analysis_techreport,
	title = "Foundations of Refinement Operators for Description Logics",
	author = "Jens Lehmann and Pascal Hitzler",
	institution = "Universit{\"a}t Leipzig",
	year = "2007",
	note = "A slightly older, but extended version including proofs of the ILP 2007 article with the same name.",
}

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