Metamath Proof Explorer


Theorem msubval

Description: A substitution applied to an expression. (Contributed by Mario Carneiro, 18-Jul-2016)

Ref Expression
Hypotheses msubffval.v ⊢ V = mVR ⁡ T
msubffval.r ⊢ R = mREx ⁡ T
msubffval.s ⊢ S = mSubst ⁡ T
msubffval.e ⊢ E = mEx ⁡ T
msubffval.o ⊢ O = mRSubst ⁡ T
Assertion msubval ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E → S ⁡ F ⁡ X = 1 st ⁡ X O ⁡ F ⁡ 2 nd ⁡ X

Proof

Step Hyp Ref Expression
1 msubffval.v ⊢ V = mVR ⁡ T
2 msubffval.r ⊢ R = mREx ⁡ T
3 msubffval.s ⊢ S = mSubst ⁡ T
4 msubffval.e ⊢ E = mEx ⁡ T
5 msubffval.o ⊢ O = mRSubst ⁡ T
6 1 2 3 4 5 msubfval ⊢ F : A ⟶ R ∧ A ⊆ V → S ⁡ F = e ∈ E ⟼ 1 st ⁡ e O ⁡ F ⁡ 2 nd ⁡ e
7 6 3adant3 ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E → S ⁡ F = e ∈ E ⟼ 1 st ⁡ e O ⁡ F ⁡ 2 nd ⁡ e
8 simpr ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E ∧ e = X → e = X
9 8 fveq2d ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E ∧ e = X → 1 st ⁡ e = 1 st ⁡ X
10 8 fveq2d ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E ∧ e = X → 2 nd ⁡ e = 2 nd ⁡ X
11 10 fveq2d ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E ∧ e = X → O ⁡ F ⁡ 2 nd ⁡ e = O ⁡ F ⁡ 2 nd ⁡ X
12 9 11 opeq12d ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E ∧ e = X → 1 st ⁡ e O ⁡ F ⁡ 2 nd ⁡ e = 1 st ⁡ X O ⁡ F ⁡ 2 nd ⁡ X
13 simp3 ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E → X ∈ E
14 opex ⊢ 1 st ⁡ X O ⁡ F ⁡ 2 nd ⁡ X ∈ V
15 14 a1i ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E → 1 st ⁡ X O ⁡ F ⁡ 2 nd ⁡ X ∈ V
16 7 12 13 15 fvmptd ⊢ F : A ⟶ R ∧ A ⊆ V ∧ X ∈ E → S ⁡ F ⁡ X = 1 st ⁡ X O ⁡ F ⁡ 2 nd ⁡ X