Metamath Proof Explorer


Theorem grpplusgx

Description: The operation of an explicitly given group. Note: This theorem has hard-coded structure indices for demonstration purposes. It is not intended for general use; use grpplusg instead. (New usage is discouraged.) (Contributed by NM, 17-Oct-2012)

Ref Expression
Hypotheses grpstrx.b ⊢ 𝐵 ∈ V
grpstrx.p ⊢ + ∈ V
grpstrx.g ⊢ 𝐺 = { ⟨ 1 , 𝐵 ⟩ , ⟨ 2 , + ⟩ }
Assertion grpplusgx + = ( +g ‘ 𝐺 )

Proof

Step Hyp Ref Expression
1 grpstrx.b ⊢ 𝐵 ∈ V
2 grpstrx.p ⊢ + ∈ V
3 grpstrx.g ⊢ 𝐺 = { ⟨ 1 , 𝐵 ⟩ , ⟨ 2 , + ⟩ }
4 basendx ⊢ ( Base ‘ ndx ) = 1
5 4 opeq1i ⊢ ⟨ ( Base ‘ ndx ) , 𝐵 ⟩ = ⟨ 1 , 𝐵 ⟩
6 plusgndx ⊢ ( +g ‘ ndx ) = 2
7 6 opeq1i ⊢ ⟨ ( +g ‘ ndx ) , + ⟩ = ⟨ 2 , + ⟩
8 5 7 preq12i ⊢ { ⟨ ( Base ‘ ndx ) , 𝐵 ⟩ , ⟨ ( +g ‘ ndx ) , + ⟩ } = { ⟨ 1 , 𝐵 ⟩ , ⟨ 2 , + ⟩ }
9 3 8 eqtr4i ⊢ 𝐺 = { ⟨ ( Base ‘ ndx ) , 𝐵 ⟩ , ⟨ ( +g ‘ ndx ) , + ⟩ }
10 9 grpplusg ⊢ ( + ∈ V → + = ( +g ‘ 𝐺 ) )
11 2 10 ax-mp ⊢ + = ( +g ‘ 𝐺 )