Metamath Proof Explorer


Theorem rngstr

Description: A constructed ring is a structure. (Contributed by Mario Carneiro, 28-Sep-2013) (Revised by Mario Carneiro, 29-Aug-2015)

Ref Expression
Hypothesis rngfn.r R=BasendxB+ndx+˙ndx·˙
Assertion rngstr RStruct13

Proof

Step Hyp Ref Expression
1 rngfn.r R=BasendxB+ndx+˙ndx·˙
2 1nn 1
3 basendx Basendx=1
4 1lt2 1<2
5 2nn 2
6 plusgndx +ndx=2
7 2lt3 2<3
8 3nn 3
9 mulrndx ndx=3
10 2 3 4 5 6 7 8 9 strle3 BasendxB+ndx+˙ndx·˙Struct13
11 1 10 eqbrtri RStruct13