CatDat

Implication Details

Claim: If a category has binary products and has equalizers, then it has pullbacks.

Proof: The pullback of f:XSf : X \to S and g:YSg : Y \to S is the equalizer of p1f,p2g:X×YSp_1 \circ f, \, p_2 \circ g : X \times Y \rightrightarrows S.

Show 39 categories using this implication