Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Power Sets
Functions
f1f
Next ⟩
f1fn
Metamath Proof Explorer
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Theorem
f1f
Description:
A one-to-one mapping is a mapping.
(Contributed by
NM
, 31-Dec-1996)
Ref
Expression
Assertion
f1f
⊢
F
:
A
⟶
1-1
B
→
F
:
A
⟶
B
Proof
Step
Hyp
Ref
Expression
1
df-f1
⊢
F
:
A
⟶
1-1
B
↔
F
:
A
⟶
B
∧
Fun
⁡
F
-1
2
1
simplbi
⊢
F
:
A
⟶
1-1
B
→
F
:
A
⟶
B