Description: Absorption into embedded conjunct. (Contributed by NM, 4-Sep-1995) (Proof shortened by Wolf Lammen, 16-Nov-2013)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | anabs1 | ⊢ ( ( ( 𝜑 ∧ 𝜓 ) ∧ 𝜑 ) ↔ ( 𝜑 ∧ 𝜓 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simpl | ⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) | |
| 2 | 1 | pm4.71i | ⊢ ( ( 𝜑 ∧ 𝜓 ) ↔ ( ( 𝜑 ∧ 𝜓 ) ∧ 𝜑 ) ) |
| 3 | 2 | bicomi | ⊢ ( ( ( 𝜑 ∧ 𝜓 ) ∧ 𝜑 ) ↔ ( 𝜑 ∧ 𝜓 ) ) |