Metamath Proof Explorer


Theorem addcnsrec

Description: Technical trick to permit re-use of some equivalence class lemmas for operation laws. See dfcnqs and mulcnsrec . (Contributed by NM, 13-Aug-1995) (New usage is discouraged.)

Ref Expression
Assertion addcnsrec A𝑹B𝑹C𝑹D𝑹ABE-1+CDE-1=A+𝑹CB+𝑹DE-1

Proof

Step Hyp Ref Expression
1 addcnsr A𝑹B𝑹C𝑹D𝑹AB+CD=A+𝑹CB+𝑹D
2 opex ABV
3 2 ecid ABE-1=AB
4 opex CDV
5 4 ecid CDE-1=CD
6 3 5 oveq12i ABE-1+CDE-1=AB+CD
7 opex A+𝑹CB+𝑹DV
8 7 ecid A+𝑹CB+𝑹DE-1=A+𝑹CB+𝑹D
9 1 6 8 3eqtr4g A𝑹B𝑹C𝑹D𝑹ABE-1+CDE-1=A+𝑹CB+𝑹DE-1