Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
Functions in maps-to notation
mpteq2iaOLD
Metamath Proof Explorer
Description: Obsolete version of mpteq2ia as of 11-Nov-2024. (Contributed by Mario
Carneiro , 16-Dec-2013) (Proof modification is discouraged.)
(New usage is discouraged.)
Ref
Expression
Hypothesis
mpteq2ia.1
⊢ ( 𝑥 ∈ 𝐴 → 𝐵 = 𝐶 )
Assertion
mpteq2iaOLD
⊢ ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) = ( 𝑥 ∈ 𝐴 ↦ 𝐶 )
Proof
Step
Hyp
Ref
Expression
1
mpteq2ia.1
⊢ ( 𝑥 ∈ 𝐴 → 𝐵 = 𝐶 )
2
eqid
⊢ 𝐴 = 𝐴
3
2
ax-gen
⊢ ∀ 𝑥 𝐴 = 𝐴
4
1
rgen
⊢ ∀ 𝑥 ∈ 𝐴 𝐵 = 𝐶
5
mpteq12f
⊢ ( ( ∀ 𝑥 𝐴 = 𝐴 ∧ ∀ 𝑥 ∈ 𝐴 𝐵 = 𝐶 ) → ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) = ( 𝑥 ∈ 𝐴 ↦ 𝐶 ) )
6
3 4 5
mp2an
⊢ ( 𝑥 ∈ 𝐴 ↦ 𝐵 ) = ( 𝑥 ∈ 𝐴 ↦ 𝐶 )