Database
SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Richard Penner
Short Studies
Additional work on conditional logical operator
ifpbiidcor
Next ⟩
ifpbicor
Metamath Proof Explorer
Ascii
Unicode
Theorem
ifpbiidcor
Description:
Restatement of
biid
.
(Contributed by
RP
, 25-Apr-2020)
Ref
Expression
Assertion
ifpbiidcor
⊢
if-
φ
φ
¬
φ
Proof
Step
Hyp
Ref
Expression
1
biid
⊢
φ
↔
φ
2
ifpdfbi
⊢
φ
↔
φ
↔
if-
φ
φ
¬
φ
3
1
2
mpbi
⊢
if-
φ
φ
¬
φ