Metamath Proof Explorer


Theorem div13

Description: A commutative/associative law for division. (Contributed by NM, 22-Apr-2005)

Ref Expression
Assertion div13 ABB0CABC=CBA

Proof

Step Hyp Ref Expression
1 mulcom ACAC=CA
2 1 oveq1d ACACB=CAB
3 2 3adant2 ABB0CACB=CAB
4 div23 ACBB0ACB=ABC
5 4 3com23 ABB0CACB=ABC
6 div23 CABB0CAB=CBA
7 6 3coml ABB0CCAB=CBA
8 3 5 7 3eqtr3d ABB0CABC=CBA