Description: Absorption into embedded conjunct. (Contributed by NM, 20-Jul-1996) (Proof shortened by Wolf Lammen, 9-Dec-2012)
Ref | Expression | ||
---|---|---|---|
Assertion | anabs5 | ⊢ ( ( 𝜑 ∧ ( 𝜑 ∧ 𝜓 ) ) ↔ ( 𝜑 ∧ 𝜓 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ibar | ⊢ ( 𝜑 → ( 𝜓 ↔ ( 𝜑 ∧ 𝜓 ) ) ) | |
2 | 1 | bicomd | ⊢ ( 𝜑 → ( ( 𝜑 ∧ 𝜓 ) ↔ 𝜓 ) ) |
3 | 2 | pm5.32i | ⊢ ( ( 𝜑 ∧ ( 𝜑 ∧ 𝜓 ) ) ↔ ( 𝜑 ∧ 𝜓 ) ) |