This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Inference associated with biadani . Add a conjunction to an equivalence. (Contributed by Jeff Madsen, 20-Jun-2011) (Proof shortened by BJ, 4-Mar-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | biadani.1 | ⊢ ( 𝜑 → 𝜓 ) | |
| biadanii.2 | ⊢ ( 𝜓 → ( 𝜑 ↔ 𝜒 ) ) | ||
| Assertion | biadanii | ⊢ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | biadani.1 | ⊢ ( 𝜑 → 𝜓 ) | |
| 2 | biadanii.2 | ⊢ ( 𝜓 → ( 𝜑 ↔ 𝜒 ) ) | |
| 3 | 1 | biadani | ⊢ ( ( 𝜓 → ( 𝜑 ↔ 𝜒 ) ) ↔ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ) ) ) |
| 4 | 2 3 | mpbi | ⊢ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ) ) |