Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical conjunction
anidmdbi
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anidms
Metamath Proof Explorer
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Theorem
anidmdbi
Description:
Conjunction idempotence with antecedent.
(Contributed by
Roy F. Longton
, 8-Aug-2005)
Ref
Expression
Assertion
anidmdbi
⊢
φ
→
ψ
∧
ψ
↔
φ
→
ψ
Proof
Step
Hyp
Ref
Expression
1
anidm
⊢
ψ
∧
ψ
↔
ψ
2
1
imbi2i
⊢
φ
→
ψ
∧
ψ
↔
φ
→
ψ