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First-order logic
Adding ax-6
bj-spimvwt
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bj-spnfw
Metamath Proof Explorer
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Theorem
bj-spimvwt
Description:
Closed form of
spimvw
. See also
spimt
.
(Contributed by
BJ
, 8-Nov-2021)
Ref
Expression
Assertion
bj-spimvwt
⊢
∀
x
x
=
y
→
φ
→
ψ
→
∀
x
φ
→
ψ
Proof
Step
Hyp
Ref
Expression
1
alequexv
⊢
∀
x
x
=
y
→
φ
→
ψ
→
∃
x
φ
→
ψ
2
19.36v
⊢
∃
x
φ
→
ψ
↔
∀
x
φ
→
ψ
3
1
2
sylib
⊢
∀
x
x
=
y
→
φ
→
ψ
→
∀
x
φ
→
ψ