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this define a sheaf as a triple $(S,\pi,X)$ such that $\pi : S \to X$ is a surjective local homeomorphism, so that $S$ is locally homeomophic to $X$, while a bundle is a triple $(E,\pi,B)$ such that $\pi : E \to B$ is a surjective continuous mapping, and this implies the direct product thing in a bundle, hmm