How To Prove Image And Preimage. Preimage of a set. Images and preimages of sets.
Image of a set. Onto functions focus on the codomain. Peggy wants to prove that she knows a preimage for a digest chosen by victor without revealing what the preimage is.
Prove that if h is bijective then there exists a function f.
Image of a set. In words the image f x of x is the set of all things in b that f sends elements of x to. Let s recall our goal. More generally evaluating a given function f at each element of a given subset a of its domain produces a set called the image of a under or through f.