Metamath Proof Explorer


Theorem mapdhval0

Description: Lemmma for ~? mapdh . (Contributed by NM, 3-Apr-2015)

Ref Expression
Hypotheses mapdh.q ⊢ Q = 0 C
mapdh.i ⊢ I = x ∈ V ⟼ if 2 nd ⁡ x = 0 ˙ Q ι h ∈ D | M ⁡ N ⁡ 2 nd ⁡ x = J ⁡ h ∧ M ⁡ N ⁡ 1 st ⁡ 1 st ⁡ x - ˙ 2 nd ⁡ x = J ⁡ 2 nd ⁡ 1 st ⁡ x R h
mapdh0.o ⊢ 0 ˙ = 0 U
mapdh0.x ⊢ φ → X ∈ A
mapdh0.f ⊢ φ → F ∈ B
Assertion mapdhval0 ⊢ φ → I ⁡ X F 0 ˙ = Q

Proof

Step Hyp Ref Expression
1 mapdh.q ⊢ Q = 0 C
2 mapdh.i ⊢ I = x ∈ V ⟼ if 2 nd ⁡ x = 0 ˙ Q ι h ∈ D | M ⁡ N ⁡ 2 nd ⁡ x = J ⁡ h ∧ M ⁡ N ⁡ 1 st ⁡ 1 st ⁡ x - ˙ 2 nd ⁡ x = J ⁡ 2 nd ⁡ 1 st ⁡ x R h
3 mapdh0.o ⊢ 0 ˙ = 0 U
4 mapdh0.x ⊢ φ → X ∈ A
5 mapdh0.f ⊢ φ → F ∈ B
6 3 fvexi ⊢ 0 ˙ ∈ V
7 6 a1i ⊢ φ → 0 ˙ ∈ V
8 1 2 4 5 7 mapdhval ⊢ φ → I ⁡ X F 0 ˙ = if 0 ˙ = 0 ˙ Q ι h ∈ D | M ⁡ N ⁡ 0 ˙ = J ⁡ h ∧ M ⁡ N ⁡ X - ˙ 0 ˙ = J ⁡ F R h
9 eqid ⊢ 0 ˙ = 0 ˙
10 9 iftruei ⊢ if 0 ˙ = 0 ˙ Q ι h ∈ D | M ⁡ N ⁡ 0 ˙ = J ⁡ h ∧ M ⁡ N ⁡ X - ˙ 0 ˙ = J ⁡ F R h = Q
11 8 10 eqtrdi ⊢ φ → I ⁡ X F 0 ˙ = Q