Theorem bj-nexrt 34874

Description: Closed form of nexr 2185. Contrapositive of 19.8a 2174. (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 2174	. 2 ⊢ (𝜑 → ∃𝑥𝜑)
2	1	con3i 154	1 ⊢ (¬ ∃𝑥𝜑 → ¬ 𝜑)

Syntax hints:  ¬ wn 3   → wi 4  ∃wex 1782

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1798  ax-4 1812  ax-5 1913  ax-6 1971  ax-7 2011  ax-12 2171

This theorem depends on definitions:  df-bi 206  df-ex 1783

This theorem is referenced by: (None)