It can refer either to correspondence theorem or to the butterfly lemma. The unique factorization property results from Euclid's lemma. It therefore suffices to prove the generalized tube lemma. A sketch of the proof of Zorn's lemma follows, assuming the axiom of choice. This proof relies on Zorn's lemma, which is equivalent to the axiom of choice. The convexity properties are consequences of Gauss's lemma and its generalisations. This follows from Zorn's lemma, an equivalent formulation of the Axiom of Choice. This is the generalization of Euclid's lemma mentioned above. This follows from a generalization of Euclid's lemma. Applying the lemma gives polar decomposition. The problem reduces to that of counting symmetric arrangements via Burnside's lemma. This can be viewed as a generalization of Euclid's lemma. Let formula 50 be a maximal extension, which clearly exists by Zorn's lemma. The Hausdorff maximal principle is an early statement similar to Zorn's lemma. Some lexemes have several stems but one lemma.