Theorem mvrraddi

Description: Move the right term in a sum on the RHS to the LHS. (Contributed by David A. Wheeler, 11-Oct-2018)

	Ref	Expression
Hypotheses	mvrraddi.1	|- B e. CC
	mvrraddi.2	|- C e. CC
	mvrraddi.3	|- A = ( B + C )
Assertion	mvrraddi	|- ( A - C ) = B

Proof

Step	Hyp	Ref	Expression
1		mvrraddi.1	|- B e. CC
2		mvrraddi.2	|- C e. CC
3		mvrraddi.3	|- A = ( B + C )
4	3	oveq1i	|- ( A - C ) = ( ( B + C ) - C )
5	1 2	pncan3oi	|- ( ( B + C ) - C ) = B
6	4 5	eqtri	|- ( A - C ) = B