Theorem ifpbiidcor2

Description: Restatement of biid . (Contributed by RP, 25-Apr-2020)

	Ref	Expression
Assertion	ifpbiidcor2	$$⊢\neg if-\left(\phi ,\neg \phi ,\phi \right)$$

Proof

Step	Hyp	Ref	Expression
1		ifpbiidcor	$$⊢if-\left(\phi ,\phi ,\neg \phi \right)$$
2		ifpnot23b	$$⊢\neg if-\left(\phi ,\neg \phi ,\phi \right)\leftrightarrow if-\left(\phi ,\phi ,\neg \phi \right)$$
3	1 2	mpbir	$$⊢\neg if-\left(\phi ,\neg \phi ,\phi \right)$$