Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical conjunction
rbaibd
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bianabs
Metamath Proof Explorer
Ascii
Unicode
Theorem
rbaibd
Description:
Move conjunction outside of biconditional.
(Contributed by
Mario Carneiro
, 11-Sep-2015)
Ref
Expression
Hypothesis
baibd.1
⊢
φ
→
ψ
↔
χ
∧
θ
Assertion
rbaibd
⊢
φ
∧
θ
→
ψ
↔
χ
Proof
Step
Hyp
Ref
Expression
1
baibd.1
⊢
φ
→
ψ
↔
χ
∧
θ
2
1
biancomd
⊢
φ
→
ψ
↔
θ
∧
χ
3
2
baibd
⊢
φ
∧
θ
→
ψ
↔
χ