Timeline for Is inclusion map not the same as identity?
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 10, 2014 at 17:07 | vote | accept | Lemon | ||
| Nov 10, 2014 at 16:55 | comment | added | user63181 | If you mean by "it's the identity on $A$" that the map $i: A\to i(A),\; x\mapsto x$ is the identity then it's right. | |
| Nov 10, 2014 at 16:52 | comment | added | Lemon | Okay I understand that it isn't the identity on $B$, but it is identity on $A$ right? | |
| Nov 10, 2014 at 16:50 | comment | added | user63181 | $i$ is surjective if $\forall b\in B$ there's $a\in A$ such that $i(a)=b$. Now take $b\in B-A$ to see that $i$ isn't surjective if $B\ne A$. | |
| Nov 10, 2014 at 16:47 | comment | added | Lemon | I mean $i(A) = A$. | |
| Nov 10, 2014 at 16:46 | comment | added | user63181 | What do you mean by surjective with $A$? | |
| Nov 10, 2014 at 16:45 | comment | added | Lemon | But it is surjective with $A$. | |
| Nov 10, 2014 at 16:44 | history | answered | user63181 | CC BY-SA 3.0 |