Theorem exmidd 909

Description: Law of excluded middle in a context. (Contributed by Mario Carneiro, 9-Feb-2017.)

Assertion

Ref	Expression
exmidd	⊢ (𝜑 → (𝜓 ∨ ¬ 𝜓))

Proof of Theorem exmidd

Step	Hyp	Ref	Expression
1		exmid 908	. 2 ⊢ (𝜓 ∨ ¬ 𝜓)
2	1	a1i 11	1 ⊢ (𝜑 → (𝜓 ∨ ¬ 𝜓))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ∨ wo 861

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

This proof depends on definitions:  df-bi 210  df-or 862

This theorem is used by:  rabxm  4347  zeo3  16417  chnccat  18704  plngrotlem1  29120  hashxpe  33222  tlt2  33353  dflring3  33851  fsumcvg4  34404  chtvalz  35081  tsor1  38854  ts3or1  38860  aks4d1p5  42905