Theorem 3anidm23 1194

Description: Inference from idempotent law for conjunction. (Contributed by NM, 1-Feb-2007.)

Hypothesis

Ref	Expression
3anidm23.1	⊢ ((𝜑 ∧ 𝜓 ∧ 𝜓) → 𝜒)

Assertion

Ref	Expression
3anidm23	⊢ ((𝜑 ∧ 𝜓) → 𝜒)

Proof of Theorem 3anidm23

Step	Hyp	Ref	Expression
1		3anidm23.1	. . 3 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜓) → 𝜒)
2	1	3expa 1104	. 2 ⊢ (((𝜑 ∧ 𝜓) ∧ 𝜓) → 𝜒)
3	2	anabss3 519	1 ⊢ ((𝜑 ∧ 𝜓) → 𝜒)

Syntax hints:   → wi 4   ∧ wa 97   ∧ w3a 885

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101

This theorem depends on definitions:  df-bi 110  df-3an 887

This theorem is referenced by:  efrirr  4090  subeq0  7237  halfaddsub  8159  avglt2  8164