Theorem bj-nexrt 34026

Description: Closed form of nexr 2191. Contrapositive of 19.8a 2180. (Contributed by BJ, 20-Oct-2019.)

Assertion

Ref	Expression
bj-nexrt	⊢ (¬ ∃𝑥𝜑 → ¬ 𝜑)

Proof of Theorem bj-nexrt

Step	Hyp	Ref	Expression
1		19.8a 2180	. 2 ⊢ (𝜑 → ∃𝑥𝜑)
2	1	con3i 157	1 ⊢ (¬ ∃𝑥𝜑 → ¬ 𝜑)

Syntax hints:  ¬ wn 3   → wi 4  ∃wex 1780

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1970  ax-7 2015  ax-12 2177

This theorem depends on definitions:  df-bi 209  df-ex 1781

This theorem is referenced by: (None)