Database
SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Peter Mazsa
Preparatory theorems
xpv
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vxp
Metamath Proof Explorer
Ascii
Unicode
Theorem
xpv
Description:
Cartesian product of a class and the universe.
(Contributed by
Peter Mazsa
, 6-Oct-2020)
Ref
Expression
Assertion
xpv
⊢
A
×
V
=
x
y
|
x
∈
A
Proof
Step
Hyp
Ref
Expression
1
df-xp
⊢
A
×
V
=
x
y
|
x
∈
A
∧
y
∈
V
2
vex
⊢
y
∈
V
3
iba
⊢
y
∈
V
→
x
∈
A
↔
x
∈
A
∧
y
∈
V
4
2
3
ax-mp
⊢
x
∈
A
↔
x
∈
A
∧
y
∈
V
5
4
opabbii
⊢
x
y
|
x
∈
A
=
x
y
|
x
∈
A
∧
y
∈
V
6
1
5
eqtr4i
⊢
A
×
V
=
x
y
|
x
∈
A