Description: Move class substitution in and out of an operation. (Contributed by NM, 12-Nov-2005)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | csbov1g | |- ( A e. V -> [_ A / x ]_ ( B F C ) = ( [_ A / x ]_ B F C ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | csbov12g | |- ( A e. V -> [_ A / x ]_ ( B F C ) = ( [_ A / x ]_ B F [_ A / x ]_ C ) ) | |
| 2 | csbconstg | |- ( A e. V -> [_ A / x ]_ C = C ) | |
| 3 | 2 | oveq2d | |- ( A e. V -> ( [_ A / x ]_ B F [_ A / x ]_ C ) = ( [_ A / x ]_ B F C ) ) | 
| 4 | 1 3 | eqtrd | |- ( A e. V -> [_ A / x ]_ ( B F C ) = ( [_ A / x ]_ B F C ) ) |