Theorem pm2.1 910

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 868	1 ⊢ (¬ 𝜑 ∨ 𝜑)

This proof depends on syntax axioms:  ¬ wn 3   ∨ 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:  lelttric  11335  hashbclem  14509  maducoeval2  22834  nofv  27858  eln0s  28591  hiidge0  31487  xrlelttric  33134  wl-orel12  38207  ifpdfor2  44228  en3lpVD  45594  fvmptrabdm  48071