Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
First and second members of an ordered pair
op2nd
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op1std
Metamath Proof Explorer
Ascii
Unicode
Theorem
op2nd
Description:
Extract the second member of an ordered pair.
(Contributed by
NM
, 5-Oct-2004)
Ref
Expression
Hypotheses
op1st.1
⊢
A
∈
V
op1st.2
⊢
B
∈
V
Assertion
op2nd
⊢
2
nd
⁡
A
B
=
B
Proof
Step
Hyp
Ref
Expression
1
op1st.1
⊢
A
∈
V
2
op1st.2
⊢
B
∈
V
3
2ndval
⊢
2
nd
⁡
A
B
=
⋃
ran
⁡
A
B
4
1
2
op2nda
⊢
⋃
ran
⁡
A
B
=
B
5
3
4
eqtri
⊢
2
nd
⁡
A
B
=
B