Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Predicate calculus with equality: Tarski's system S2 (1 rule, 6 schemes)
Axiom scheme ax-4 (Quantified Implication)
ala1
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al2im
Metamath Proof Explorer
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Theorem
ala1
Description:
Add an antecedent in a universally quantified formula.
(Contributed by
BJ
, 6-Oct-2018)
Ref
Expression
Assertion
ala1
⊢
∀
x
φ
→
∀
x
ψ
→
φ
Proof
Step
Hyp
Ref
Expression
1
ax-1
⊢
φ
→
ψ
→
φ
2
1
alimi
⊢
∀
x
φ
→
∀
x
ψ
→
φ