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2020年4月15日 · Injectivity and surjectivity are very intimately related, however, in any particular structure, one of them tends to be a much "harder" property - just looking at basic set theory, we have that a function is injective iff it has a left inverse, and surjective iff it has a right inverse.

2020年9月2日 · The way I see it, it states that if I have 2 different mappings, they have to come from different inputs, which would be consistent with the definition of injectivity. What am I missing? $\endgroup$ – Paul92

Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

2015年10月14日 · We were told in class that when we proved that a function between two vector spaces is injective and surjective, essentially we were proving that a basis for the vector space is linearly independen...

2016年1月12日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

2019年4月7日 · $\begingroup$ Injectivity is really very short by contrapositive. $\endgroup$ – Bernard. Commented Apr 7

2011年9月9日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Neither "injectivity" nor "injectiveness" have made it to the Oxford English Dictionary. A MathSciNet search for titles containing "injectivity" yields 702 hits, but "injectiveness" just 7. So I'd say "injectivity" is the clear winner.