CatDat

Implication Details

Claim: Given a functor whose domain is regular-quotient-trivial, then it preserves coreflexive equalizers.

Proof: Let f,g:XYf,g : X \rightrightarrows Y be a coreflexive pair, i.e. there is a morphism r:YXr : Y \to X with rf=rg=idXrf = rg = \id_X. Then rr is a split and hence a regular epimorphism. Thus, rr is an isomorphism. But then f=gf=g, and idX\id_X is an equalizer of f,gf,g. This equalizer is obviously preserved.

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