Theorem pm2.1 909

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 23	. 2 ⊢ (𝜑 → 𝜑)
2	1	imori 867	1 ⊢ (¬ 𝜑 ∨ 𝜑)

Syntax hints:  ¬ wn 3   ∨ wo 860

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 210  df-or 861

This theorem is referenced by:  lelttric  11305  hashbclem  14479  maducoeval2  22758  nofv  27779  eln0s  28512  hiidge0  31359  xrlelttric  33009  wl-orel12  38026  ifpdfor2  44049  en3lpVD  45418  fvmptrabdm  47885