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CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Predicate calculus with equality: Tarski's system S2 (1 rule, 6 schemes)
Axiom scheme ax-4 (Quantified Implication)
19.33
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19.33b
Metamath Proof Explorer
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Unicode
Theorem
19.33
Description:
Theorem 19.33 of
Margaris
p. 90.
(Contributed by
NM
, 12-Mar-1993)
Ref
Expression
Assertion
19.33
⊢
∀
x
φ
∨
∀
x
ψ
→
∀
x
φ
∨
ψ
Proof
Step
Hyp
Ref
Expression
1
orc
⊢
φ
→
φ
∨
ψ
2
1
alimi
⊢
∀
x
φ
→
∀
x
φ
∨
ψ
3
olc
⊢
ψ
→
φ
∨
ψ
4
3
alimi
⊢
∀
x
ψ
→
∀
x
φ
∨
ψ
5
2
4
jaoi
⊢
∀
x
φ
∨
∀
x
ψ
→
∀
x
φ
∨
ψ