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 ⊢ ( 𝜑 → 𝐵 ∈ ℂ )
raddswap12d.c ⊢ ( 𝜑 → 𝐶 ∈ ℂ )
raddswap12d.1 ⊢ ( 𝜑 → 𝐴 = ( 𝐵 + 𝐶 ) )
Assertion raddswap12d ( 𝜑 → 𝐵 = ( 𝐴 − 𝐶 ) )

Proof

Step Hyp Ref Expression
1 raddswap12d.b ⊢ ( 𝜑 → 𝐵 ∈ ℂ )
2 raddswap12d.c ⊢ ( 𝜑 → 𝐶 ∈ ℂ )
3 raddswap12d.1 ⊢ ( 𝜑 → 𝐴 = ( 𝐵 + 𝐶 ) )
4 1 2 3 mvrraddd ⊢ ( 𝜑 → ( 𝐴 − 𝐶 ) = 𝐵 )
5 4 eqcomd ⊢ ( 𝜑 → 𝐵 = ( 𝐴 − 𝐶 ) )