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Theorem r19.21be 2716
Description: Inference from Theorem 19.21 of [Margaris] p. 90. (Restricted quantifier version.) (Contributed by NM, 21-Nov-1994.)
Hypothesis
Ref Expression
r19.21be.1 ⊢ (φ → ∀x ∈ A ψ)
Assertion
Ref Expression
r19.21be ⊢ ∀x ∈ A (φ → ψ)

Proof of Theorem r19.21be
StepHypRef Expression
1 r19.21be.1 . . . 4 ⊢ (φ → ∀x ∈ A ψ)
21r19.21bi 2713 . . 3 ⊢ ((φ ∧ x ∈ A) → ψ)
32expcom 424 . 2 ⊢ (x ∈ A → (φ → ψ))
43rgen 2680 1 ⊢ ∀x ∈ A (φ → ψ)
Colors of variables:    wff setvar class
This proof depends on syntax axioms:   → wi 4   ∈ wcel 1710  ∀wral 2615
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-11 1746
This proof depends on definitions:  df-bi 177  df-an 360  df-ex 1542  df-ral 2620
This theorem is used by: (None)
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