Metamath Proof Explorer


Theorem frlmval

Description: Value of the "free module" function. (Contributed by Stefan O'Rear, 1-Feb-2015)

Ref Expression
Hypothesis frlmval.f ⊢ F = R freeLMod I
Assertion frlmval ⊢ R ∈ V ∧ I ∈ W → F = R ⊕ m I × ringLMod ⁡ R

Proof

Step Hyp Ref Expression
1 frlmval.f ⊢ F = R freeLMod I
2 elex ⊢ R ∈ V → R ∈ V
3 elex ⊢ I ∈ W → I ∈ V
4 id ⊢ r = R → r = R
5 fveq2 ⊢ r = R → ringLMod ⁡ r = ringLMod ⁡ R
6 5 sneqd ⊢ r = R → ringLMod ⁡ r = ringLMod ⁡ R
7 6 xpeq2d ⊢ r = R → i × ringLMod ⁡ r = i × ringLMod ⁡ R
8 4 7 oveq12d ⊢ r = R → r ⊕ m i × ringLMod ⁡ r = R ⊕ m i × ringLMod ⁡ R
9 xpeq1 ⊢ i = I → i × ringLMod ⁡ R = I × ringLMod ⁡ R
10 9 oveq2d ⊢ i = I → R ⊕ m i × ringLMod ⁡ R = R ⊕ m I × ringLMod ⁡ R
11 df-frlm ⊢ freeLMod = r ∈ V , i ∈ V ⟼ r ⊕ m i × ringLMod ⁡ r
12 ovex ⊢ R ⊕ m I × ringLMod ⁡ R ∈ V
13 8 10 11 12 ovmpo ⊢ R ∈ V ∧ I ∈ V → R freeLMod I = R ⊕ m I × ringLMod ⁡ R
14 2 3 13 syl2an ⊢ R ∈ V ∧ I ∈ W → R freeLMod I = R ⊕ m I × ringLMod ⁡ R
15 1 14 eqtrid ⊢ R ∈ V ∧ I ∈ W → F = R ⊕ m I × ringLMod ⁡ R