Theorem pm2.1 897

Description: Theorem *2.1 of [WhiteheadRussell] p. 101. (Contributed by NM, 3-Jan-2005.) (Proof shortened by Wolf Lammen, 23-Nov-2012.)

Assertion

Ref	Expression
pm2.1	⊢ (¬ 𝜑 ∨ 𝜑)

Proof of Theorem pm2.1

Step	Hyp	Ref	Expression
1		id 22	. 2 ⊢ (𝜑 → 𝜑)
2	1	imori 855	1 ⊢ (¬ 𝜑 ∨ 𝜑)

Syntax hints:  ¬ wn 3   ∨ wo 848

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 207  df-or 849

This theorem is referenced by:  lelttric  11368  hashbclem  14491  maducoeval2  22646  nofv  27702  eln0s  28358  hiidge0  31117  xrlelttric  32756  wl-orel12  37512  ifpdfor2  43474  en3lpVD  44865  fvmptrabdm  47305