Metamath Proof Explorer


Theorem sraaddg

Description: Additive operation of a subring algebra. (Contributed by Stefan O'Rear, 27-Nov-2014) (Revised by Mario Carneiro, 4-Oct-2015) (Revised by Thierry Arnoux, 16-Jun-2019)

Ref Expression
Hypotheses srapart.a
|- ( ph -> A = ( ( subringAlg ` W ) ` S ) )
srapart.s
|- ( ph -> S C_ ( Base ` W ) )
Assertion sraaddg
|- ( ph -> ( +g ` W ) = ( +g ` A ) )

Proof

Step Hyp Ref Expression
1 srapart.a
 |-  ( ph -> A = ( ( subringAlg ` W ) ` S ) )
2 srapart.s
 |-  ( ph -> S C_ ( Base ` W ) )
3 df-plusg
 |-  +g = Slot 2
4 2nn
 |-  2 e. NN
5 2lt5
 |-  2 < 5
6 5 orci
 |-  ( 2 < 5 \/ 8 < 2 )
7 1 2 3 4 6 sralem
 |-  ( ph -> ( +g ` W ) = ( +g ` A ) )