Discrete math surjective function proof
6023
Surjectivity of Composition of Surjective Functions
37951
proof detail concerning bijection between a set and its power set
74453
Injective and Surjective Functions
105455
Prove that "injective function $f:X\to Y$ exists" and "surjective function $g:Y\to X$ exists" is logically equivalent.
92359
Big-O Notation Proof
93102
prove that $f:X\rightarrow Y$ is surjective if and only if $f(f^{-1}(C))=C$
72251
$g\circ f$ is Surjective and $g$ is Injective then Prove that $f$ is surjective
28798
Proving injection and surjection with functions $F:C^B\to C^A$, $F(f)=f\circ\varphi$, $\varphi: A\to B$
121395
Let $X$ and $Y$ be non-empty sets and let $f:X \rightarrow Y$. Prove that $ f^{ −1} :P(Y ) → P(X) $ is injective if, and only if, $f$ is surjective.
1821
Proving $f(C) \setminus f(D) \subseteq f(C \setminus D)$ and disproving equality
78698
Prove if $f$ has a right inverse function: $f\circ g=id_x$ $\iff$ $f$ is onto $Y$
117793
Finding a function $\mathbb{N} \to \mathbb{N}$ that is surjective but not injective.
96202
Prove composition of bijections is bijection
23125
Prove that there is a bijection between the set of all subsets of $X$, $P(X)$, and the set of functions from $X$ to $\{0,1\}$.
142534
Proof of $k {n\choose k} = n {n-1 \choose k-1}$ using direct proof
64583
Number of surjective functions from A to B
35953
Prove that a function is not injective