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 = Base ndx B + ndx + ˙ ndx · ˙
Assertion rngstr R Struct 1 3

Proof

Step Hyp Ref Expression
1 rngfn.r R = Base ndx B + ndx + ˙ ndx · ˙
2 1nn 1
3 basendx Base ndx = 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 Base ndx B + ndx + ˙ ndx · ˙ Struct 1 3
11 1 10 eqbrtri R Struct 1 3