Metamath Proof Explorer


Theorem 2zrngasgrp

Description: R is an (additive) semigroup. (Contributed by AV, 4-Feb-2020)

Ref Expression
Hypotheses 2zrng.e E = z | x z = 2 x
2zrngbas.r R = fld 𝑠 E
Assertion 2zrngasgrp R Smgrp

Proof

Step Hyp Ref Expression
1 2zrng.e E = z | x z = 2 x
2 2zrngbas.r R = fld 𝑠 E
3 1 2 2zrngamgm R Mgm
4 elrabi a z | x z = 2 x a
5 elrabi y z | x z = 2 x y
6 elrabi b z | x z = 2 x b
7 4 5 6 3anim123i a z | x z = 2 x y z | x z = 2 x b z | x z = 2 x a y b
8 zcn a a
9 zcn y y
10 zcn b b
11 8 9 10 3anim123i a y b a y b
12 addass a y b a + y + b = a + y + b
13 7 11 12 3syl a z | x z = 2 x y z | x z = 2 x b z | x z = 2 x a + y + b = a + y + b
14 13 rgen3 a z | x z = 2 x y z | x z = 2 x b z | x z = 2 x a + y + b = a + y + b
15 1 2 2zrngbas E = Base R
16 1 15 eqtr3i z | x z = 2 x = Base R
17 1 2 2zrngadd + = + R
18 16 17 issgrp R Smgrp R Mgm a z | x z = 2 x y z | x z = 2 x b z | x z = 2 x a + y + b = a + y + b
19 3 14 18 mpbir2an R Smgrp