Metamath Proof Explorer


Theorem dvne0f1

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 φA
dvne0.b φB
dvne0.f φF:ABcn
dvne0.d φdomF=AB
dvne0.z φ¬0ranF
Assertion dvne0f1 φF:AB1-1

Proof

Step Hyp Ref Expression
1 dvne0.a φA
2 dvne0.b φB
3 dvne0.f φF:ABcn
4 dvne0.d φdomF=AB
5 dvne0.z φ¬0ranF
6 1 2 3 4 5 dvne0 φFIsom<,<ABranFFIsom<,<-1ABranF
7 isof1o FIsom<,<ABranFF:AB1-1 ontoranF
8 isof1o FIsom<,<-1ABranFF:AB1-1 ontoranF
9 7 8 jaoi FIsom<,<ABranFFIsom<,<-1ABranFF:AB1-1 ontoranF
10 f1of1 F:AB1-1 ontoranFF:AB1-1ranF
11 6 9 10 3syl φF:AB1-1ranF
12 cncff F:ABcnF:AB
13 frn F:ABranF
14 3 12 13 3syl φranF
15 f1ss F:AB1-1ranFranFF:AB1-1
16 11 14 15 syl2anc φF:AB1-1