Theorem bj-ssbid2

Description: A special case of sbequ2 . (Contributed by BJ, 22-Dec-2020)

	Ref	Expression
Assertion	bj-ssbid2	$$⊢\left[x/x\right]\phi \to \phi$$

Proof

Step	Hyp	Ref	Expression
1		equid	$$⊢x=x$$
2		sbequ2	$$⊢x=x\to \left(\left[x/x\right]\phi \to \phi \right)$$
3	1 2	ax-mp	$$⊢\left[x/x\right]\phi \to \phi$$