Sunday, 17 August 2014

elementary set theory - Show that, for any infinite set X, there exists an injective but non-surjective map and a surjective but non-injective map

Show that, FOR ANY infinite set X, there exists:
(i) an injective but non-surjective map h : X → X,
(ii) a surjective but non-injective map h : X → X.



really tripped up at this saying "for any". I feel like I cant just show one example. If there is something good I can read on this please link.

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