Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical conjunction
baib
Next ⟩
baibr
Metamath Proof Explorer
Ascii
Unicode
Theorem
baib
Description:
Move conjunction outside of biconditional.
(Contributed by
NM
, 13-May-1999)
Ref
Expression
Hypothesis
baib.1
⊢
φ
↔
ψ
∧
χ
Assertion
baib
⊢
ψ
→
φ
↔
χ
Proof
Step
Hyp
Ref
Expression
1
baib.1
⊢
φ
↔
ψ
∧
χ
2
ibar
⊢
ψ
→
χ
↔
ψ
∧
χ
3
1
2
bitr4id
⊢
ψ
→
φ
↔
χ