Metamath Proof Explorer
Description: Deduce an equivalence from two implications. Variant of impbid .
(Contributed by NM, 17-Feb-2007)
|
|
Ref |
Expression |
|
Hypotheses |
impbida.1 |
⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜒 ) |
|
|
impbida.2 |
⊢ ( ( 𝜑 ∧ 𝜒 ) → 𝜓 ) |
|
Assertion |
impbida |
⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
impbida.1 |
⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜒 ) |
2 |
|
impbida.2 |
⊢ ( ( 𝜑 ∧ 𝜒 ) → 𝜓 ) |
3 |
1
|
ex |
⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) |
4 |
2
|
ex |
⊢ ( 𝜑 → ( 𝜒 → 𝜓 ) ) |
5 |
3 4
|
impbid |
⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) |