preimageWiktionary 原文构词拆分pre-前缀Before; physically in front of. · Before; earlier in time; beforehand.+image词根/词干词源说明From pre- + image.释义（英文）名词 Noun(mathematics) For a given function, the set of all elements of the domain that are mapped into a given subset of the codomain; (formally) given a function ƒ : X → Y and a subset B ⊆ Y, the set ƒ−1(B) = {x ∈ X : ƒ(x) ∈ B}.词族派生词（1）preimage attack相关词（1）image