Metamath Proof Explorer


Theorem csbconstgOLD

Description: Obsolete version of csbconstg as of 15-Oct-2024. (Contributed by Alan Sare, 22-Jul-2012) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion csbconstgOLD
|- ( A e. V -> [_ A / x ]_ B = B )

Proof

Step Hyp Ref Expression
1 nfcv
 |-  F/_ x B
2 1 csbconstgf
 |-  ( A e. V -> [_ A / x ]_ B = B )