Manuscript Em01-B@3 · Em01-B-v3.tex · proposition · 69189992

Proposition: Descent criterion

Reconstruction obstruction and conditional limit tools › Descent and the degree-four diagnostic · lines 1437–1454 · proof included or linked

Em01-B@3#prop:descent

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A linear map defines a unique map on exactly when

Continuity of the lifted map gives continuity of the descended map for the quotient topology.

Proof. Two presentations have the same reconstruction exactly when their difference belongs to . Annihilating this kernel makes the proposed image independent of the representative. The quotient universal property proves the continuity statement.

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