Surjection/Definition
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< Surjection
Revision as of 17:42, 10 May 2015 by Alec (Talk | contribs) (Created page with "Given a function {{M|f:X\rightarrow Y}}, we say {{M|f}} is ''surjective'' if: * <math>\forall y\in Y\exists x\in X[f(x)=y]</math> * Equivalently <math>\forall y\i...")
Given a function f:X→Y, we say f is surjective if:
- ∀y∈Y∃x∈X[f(x)=y]
- Equivalently ∀y∈Ythe set f−1(y)is non-empty. That is f−1(y)≠∅
