Database
SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Zhi Wang
Propositional calculus
mpbiran3d
Metamath Proof Explorer
Description: Equivalence with a conjunction one of whose conjuncts is a consequence
of the other. Deduction form. (Contributed by Zhi Wang , 24-Sep-2024)
Ref
Expression
Hypotheses
mpbiran3d.1
⊢ ( 𝜑 → ( 𝜓 ↔ ( 𝜒 ∧ 𝜃 ) ) )
mpbiran3d.2
⊢ ( ( 𝜑 ∧ 𝜒 ) → 𝜃 )
Assertion
mpbiran3d
⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) )
Proof
Step
Hyp
Ref
Expression
1
mpbiran3d.1
⊢ ( 𝜑 → ( 𝜓 ↔ ( 𝜒 ∧ 𝜃 ) ) )
2
mpbiran3d.2
⊢ ( ( 𝜑 ∧ 𝜒 ) → 𝜃 )
3
1
simprbda
⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜒 )
4
3
ex
⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) )
5
2
ex
⊢ ( 𝜑 → ( 𝜒 → 𝜃 ) )
6
5
ancld
⊢ ( 𝜑 → ( 𝜒 → ( 𝜒 ∧ 𝜃 ) ) )
7
6 1
sylibrd
⊢ ( 𝜑 → ( 𝜒 → 𝜓 ) )
8
4 7
impbid
⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) )