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Description: Deduction adding a left conjunct to both sides of a logical equivalence. (Contributed by NM, 11-May-1993) (Proof shortened by Wolf Lammen, 16-Nov-2013)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | anbid.1 | ⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) | |
| Assertion | anbi2d | ⊢ ( 𝜑 → ( ( 𝜃 ∧ 𝜓 ) ↔ ( 𝜃 ∧ 𝜒 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | anbid.1 | ⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) | |
| 2 | 1 | a1d | ⊢ ( 𝜑 → ( 𝜃 → ( 𝜓 ↔ 𝜒 ) ) ) |
| 3 | 2 | pm5.32d | ⊢ ( 𝜑 → ( ( 𝜃 ∧ 𝜓 ) ↔ ( 𝜃 ∧ 𝜒 ) ) ) |