Metamath Proof Explorer


Theorem raddswap12d

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.

EDITORIAL: The label for this theorem is questionable. Do not move until it would have 7 uses: current additional uses: (none). (Contributed by SN, 21-Aug-2024)

Ref Expression
Hypotheses raddswap12d.b
|- ( ph -> B e. CC )
raddswap12d.c
|- ( ph -> C e. CC )
raddswap12d.1
|- ( ph -> A = ( B + C ) )
Assertion raddswap12d
|- ( ph -> B = ( A - C ) )

Proof

Step Hyp Ref Expression
1 raddswap12d.b
 |-  ( ph -> B e. CC )
2 raddswap12d.c
 |-  ( ph -> C e. CC )
3 raddswap12d.1
 |-  ( ph -> A = ( B + C ) )
4 1 2 3 mvrraddd
 |-  ( ph -> ( A - C ) = B )
5 4 eqcomd
 |-  ( ph -> B = ( A - C ) )