Theorem csbieOLD

Description: Obsolete version of csbie as of 15-Oct-2024. (Contributed by AV, 2-Dec-2019) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Hypotheses	csbieOLD.1	$$⊢A\in \mathrm{V}$$
	csbieOLD.2	$$⊢x=A\to B=C$$
Assertion	csbieOLD	$$⊢⦋A/x⦌B=C$$

Proof

Step	Hyp	Ref	Expression
1		csbieOLD.1	$$⊢A\in \mathrm{V}$$
2		csbieOLD.2	$$⊢x=A\to B=C$$
3		nfcv	$$⊢\underset{\_}{Ⅎ}xC$$
4	1 3 2	csbief	$$⊢⦋A/x⦌B=C$$