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Theorem r19.22i2 1274
Description: Inference quantifying both antecedent and consequent, based on Theorem 19.22 of [Margaris] p. 90.
Hypothesis
Ref Expression
r19.22i2.1 ((xAφ) → (xBψ))
Assertion
Ref Expression
r19.22i2 (∃xA φ → ∃xB ψ)

Proof of Theorem r19.22i2
StepHypRef Expression
1 r19.22i2.1 . . 3 ((xAφ) → (xBψ))
2119.22i 723 . 2 (∃x(xAφ) → ∃x(xBψ))
3 df-rex 1206 . 2 (∃xA φ ↔ ∃x(xAφ))
4 df-rex 1206 . 2 (∃xB ψ ↔ ∃x(xBψ))
52, 3, 43imtr4 192 1 (∃xA φ → ∃xB ψ)
Colors of variables: wff set class
Syntax hints:   → wi 2   ∧ wa 196  ∃wex 678   ∈ wcel 1092  ∃wrex 1202
This theorem is referenced by:  pssnn 3428  btwnz 4613  sqr2irr 4782
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-gen 677
This theorem depends on definitions:  df-bi 128  df-an 198  df-ex 679  df-rex 1206
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