Theorem simplim 163

Description: Simplification. Similar to Theorem *3.26 (Simp) of [WhiteheadRussell] p. 112. (Contributed by NM, 3-Jan-1993.) (Proof shortened by Wolf Lammen, 21-Jul-2012.)

Assertion

Ref	Expression
simplim	⊢ (¬ (𝜑 → 𝜓) → 𝜑)

Proof of Theorem simplim

Step	Hyp	Ref	Expression
1		pm2.21 120	. 2 ⊢ (¬ 𝜑 → (𝜑 → 𝜓))
2	1	con1i 144	1 ⊢ (¬ (𝜑 → 𝜓) → 𝜑)

Syntax hints:  ¬ wn 3   → wi 4

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

This theorem is referenced by:  pm2.5  164  pm2.521  166  impt  169  peirce  193  dfbi1  203  biimp  205  imbi12  336  pm4.79  607  mptbi12f  33975  ac6s6  33980  rp-fakeimass  37857