Theorem exmidd 405

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 404	. 2 ⊢ (ψ ∨ ¬ ψ)
2	1	a1i 10	1 ⊢ (φ → (ψ ∨ ¬ ψ))

Syntax hints:  ¬ wn 3   → wi 4   ∨ wo 357

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 177  df-or 359

This theorem is referenced by: (None)