Description: Cancelling a term on the right-hand side of a sum in an equality. Consequence of addcan2d . (Contributed by David Moews, 28-Feb-2017)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | muld.1 | |- ( ph -> A e. CC ) | |
| addcomd.2 | |- ( ph -> B e. CC ) | ||
| addcand.3 | |- ( ph -> C e. CC ) | ||
| addcan2ad.4 | |- ( ph -> ( A + C ) = ( B + C ) ) | ||
| Assertion | addcan2ad | |- ( ph -> A = B ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | muld.1 | |- ( ph -> A e. CC ) | |
| 2 | addcomd.2 | |- ( ph -> B e. CC ) | |
| 3 | addcand.3 | |- ( ph -> C e. CC ) | |
| 4 | addcan2ad.4 | |- ( ph -> ( A + C ) = ( B + C ) ) | |
| 5 | 1 2 3 | addcan2d | |- ( ph -> ( ( A + C ) = ( B + C ) <-> A = B ) ) | 
| 6 | 4 5 | mpbid | |- ( ph -> A = B ) |