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  11345  hashbclem  14521  maducoeval2  22868  nofv  27901  eln0s  28634  hiidge0  31587  xrlelttric  33231  wl-orel12  38282  ifpdfor2  44309  en3lpVD  45675  fvmptrabdm  48189