Metamath Proof Explorer


Theorem raddcom12d

Description: Swap the first two variables in an equation with addition on the right, converting it into a subtraction. Version of mvrraddd with a commuted consequent, and of mvlraddd with a commuted hypothesis. (Contributed by SN, 21-Aug-2024)

Ref Expression
Hypotheses raddcom12d.b
|- ( ph -> B e. CC )
raddcom12d.c
|- ( ph -> C e. CC )
raddcom12d.1
|- ( ph -> A = ( B + C ) )
Assertion raddcom12d
|- ( ph -> B = ( A - C ) )

Proof

Step Hyp Ref Expression
1 raddcom12d.b
 |-  ( ph -> B e. CC )
2 raddcom12d.c
 |-  ( ph -> C e. CC )
3 raddcom12d.1
 |-  ( ph -> A = ( B + C ) )
4 1 2 3 mvrraddd
 |-  ( ph -> ( A - C ) = B )
5 4 eqcomd
 |-  ( ph -> B = ( A - C ) )