Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
Unordered and ordered pairs
oteq3
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oteq1d
Metamath Proof Explorer
Ascii
Unicode
Theorem
oteq3
Description:
Equality theorem for ordered triples.
(Contributed by
NM
, 3-Apr-2015)
Ref
Expression
Assertion
oteq3
⊢
A
=
B
→
C
D
A
=
C
D
B
Proof
Step
Hyp
Ref
Expression
1
opeq2
⊢
A
=
B
→
C
D
A
=
C
D
B
2
df-ot
⊢
C
D
A
=
C
D
A
3
df-ot
⊢
C
D
B
=
C
D
B
4
1
2
3
3eqtr4g
⊢
A
=
B
→
C
D
A
=
C
D
B