Theorem 19.35ri 1908

Description: Inference associated with 19.35 1906. (Contributed by NM, 12-Mar-1993.)

Hypothesis

Ref	Expression
19.35ri.1	⊢ (∀𝑥𝜑 → ∃𝑥𝜓)

Assertion

Ref	Expression
19.35ri	⊢ ∃𝑥(𝜑 → 𝜓)

Proof of Theorem 19.35ri

Step	Hyp	Ref	Expression
1		19.35ri.1	. 2 ⊢ (∀𝑥𝜑 → ∃𝑥𝜓)
2		19.35 1906	. 2 ⊢ (∃𝑥(𝜑 → 𝜓) ↔ (∀𝑥𝜑 → ∃𝑥𝜓))
3	1, 2	mpbir 234	1 ⊢ ∃𝑥(𝜑 → 𝜓)

This proof depends on syntax axioms:   → wi 4  ∀wal 1567  ∃wex 1808

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838

This proof depends on definitions:  df-bi 210  df-ex 1809

This theorem is used by:  qexmid  2228  axrep1  5238  axextnd  10582  axinfnd  10597