Metamath Proof Explorer


Theorem div13d

Description: A commutative/associative law for division. (Contributed by Mario Carneiro, 27-May-2016)

Ref Expression
Hypotheses div1d.1 φA
divcld.2 φB
divmuld.3 φC
divmuld.4 φB0
Assertion div13d φABC=CBA

Proof

Step Hyp Ref Expression
1 div1d.1 φA
2 divcld.2 φB
3 divmuld.3 φC
4 divmuld.4 φB0
5 div13 ABB0CABC=CBA
6 1 2 4 3 5 syl121anc φABC=CBA