Description: A function on a closed interval with nonzero derivative is one-to-one. (Contributed by Mario Carneiro, 19-Feb-2015)
Ref | Expression | ||
---|---|---|---|
Hypotheses | dvne0.a | |
|
dvne0.b | |
||
dvne0.f | |
||
dvne0.d | |
||
dvne0.z | |
||
Assertion | dvne0f1 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dvne0.a | |
|
2 | dvne0.b | |
|
3 | dvne0.f | |
|
4 | dvne0.d | |
|
5 | dvne0.z | |
|
6 | 1 2 3 4 5 | dvne0 | |
7 | isof1o | |
|
8 | isof1o | |
|
9 | 7 8 | jaoi | |
10 | f1of1 | |
|
11 | 6 9 10 | 3syl | |
12 | cncff | |
|
13 | frn | |
|
14 | 3 12 13 | 3syl | |
15 | f1ss | |
|
16 | 11 14 15 | syl2anc | |