Let A be a set. Injective functions, surjective, by bijective A to A form a group? I don't know how to explain it.
Let this functions form a group?
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linear-algebra
group-theory
functions
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0Well, in order to form a group, you should need a group operation. Is it composition, addition, derivation...? Then, what is the definition of a group? Can you prove that your set of functions form (or don't form) a group? – 2017-02-01
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0The text doesn't specify – 2017-02-01
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0The group operation is composition of functions of course, domain and range are $A$. – 2017-02-01
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0The text may not specify, but your imagination may suffice. Consider functions from the set $A$ to itself. What kind of binary operation on that set can you imagine? – 2017-02-01