| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | pjfval.k | . 2
⊢ 𝐾 = (proj‘𝑊) | 
| 2 |  | fveq2 6906 | . . . . . . 7
⊢ (𝑤 = 𝑊 → (LSubSp‘𝑤) = (LSubSp‘𝑊)) | 
| 3 |  | pjfval.l | . . . . . . 7
⊢ 𝐿 = (LSubSp‘𝑊) | 
| 4 | 2, 3 | eqtr4di 2795 | . . . . . 6
⊢ (𝑤 = 𝑊 → (LSubSp‘𝑤) = 𝐿) | 
| 5 |  | fveq2 6906 | . . . . . . . 8
⊢ (𝑤 = 𝑊 → (proj1‘𝑤) =
(proj1‘𝑊)) | 
| 6 |  | pjfval.p | . . . . . . . 8
⊢ 𝑃 = (proj1‘𝑊) | 
| 7 | 5, 6 | eqtr4di 2795 | . . . . . . 7
⊢ (𝑤 = 𝑊 → (proj1‘𝑤) = 𝑃) | 
| 8 |  | eqidd 2738 | . . . . . . 7
⊢ (𝑤 = 𝑊 → 𝑥 = 𝑥) | 
| 9 |  | fveq2 6906 | . . . . . . . . 9
⊢ (𝑤 = 𝑊 → (ocv‘𝑤) = (ocv‘𝑊)) | 
| 10 |  | pjfval.o | . . . . . . . . 9
⊢  ⊥ =
(ocv‘𝑊) | 
| 11 | 9, 10 | eqtr4di 2795 | . . . . . . . 8
⊢ (𝑤 = 𝑊 → (ocv‘𝑤) = ⊥ ) | 
| 12 | 11 | fveq1d 6908 | . . . . . . 7
⊢ (𝑤 = 𝑊 → ((ocv‘𝑤)‘𝑥) = ( ⊥ ‘𝑥)) | 
| 13 | 7, 8, 12 | oveq123d 7452 | . . . . . 6
⊢ (𝑤 = 𝑊 → (𝑥(proj1‘𝑤)((ocv‘𝑤)‘𝑥)) = (𝑥𝑃( ⊥ ‘𝑥))) | 
| 14 | 4, 13 | mpteq12dv 5233 | . . . . 5
⊢ (𝑤 = 𝑊 → (𝑥 ∈ (LSubSp‘𝑤) ↦ (𝑥(proj1‘𝑤)((ocv‘𝑤)‘𝑥))) = (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥)))) | 
| 15 |  | fveq2 6906 | . . . . . . . 8
⊢ (𝑤 = 𝑊 → (Base‘𝑤) = (Base‘𝑊)) | 
| 16 |  | pjfval.v | . . . . . . . 8
⊢ 𝑉 = (Base‘𝑊) | 
| 17 | 15, 16 | eqtr4di 2795 | . . . . . . 7
⊢ (𝑤 = 𝑊 → (Base‘𝑤) = 𝑉) | 
| 18 | 17, 17 | oveq12d 7449 | . . . . . 6
⊢ (𝑤 = 𝑊 → ((Base‘𝑤) ↑m (Base‘𝑤)) = (𝑉 ↑m 𝑉)) | 
| 19 | 18 | xpeq2d 5715 | . . . . 5
⊢ (𝑤 = 𝑊 → (V × ((Base‘𝑤) ↑m
(Base‘𝑤))) = (V
× (𝑉
↑m 𝑉))) | 
| 20 | 14, 19 | ineq12d 4221 | . . . 4
⊢ (𝑤 = 𝑊 → ((𝑥 ∈ (LSubSp‘𝑤) ↦ (𝑥(proj1‘𝑤)((ocv‘𝑤)‘𝑥))) ∩ (V × ((Base‘𝑤) ↑m
(Base‘𝑤)))) = ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉)))) | 
| 21 |  | df-pj 21723 | . . . 4
⊢ proj =
(𝑤 ∈ V ↦ ((𝑥 ∈ (LSubSp‘𝑤) ↦ (𝑥(proj1‘𝑤)((ocv‘𝑤)‘𝑥))) ∩ (V × ((Base‘𝑤) ↑m
(Base‘𝑤))))) | 
| 22 | 3 | fvexi 6920 | . . . . . . 7
⊢ 𝐿 ∈ V | 
| 23 | 22 | inex1 5317 | . . . . . 6
⊢ (𝐿 ∩ V) ∈
V | 
| 24 |  | ovex 7464 | . . . . . . 7
⊢ (𝑉 ↑m 𝑉) ∈ V | 
| 25 | 24 | inex2 5318 | . . . . . 6
⊢ (V ∩
(𝑉 ↑m 𝑉)) ∈ V | 
| 26 | 23, 25 | xpex 7773 | . . . . 5
⊢ ((𝐿 ∩ V) × (V ∩
(𝑉 ↑m 𝑉))) ∈ V | 
| 27 |  | eqid 2737 | . . . . . . . 8
⊢ (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) = (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) | 
| 28 |  | ovexd 7466 | . . . . . . . 8
⊢ (𝑥 ∈ 𝐿 → (𝑥𝑃( ⊥ ‘𝑥)) ∈ V) | 
| 29 | 27, 28 | fmpti 7132 | . . . . . . 7
⊢ (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))):𝐿⟶V | 
| 30 |  | fssxp 6763 | . . . . . . 7
⊢ ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))):𝐿⟶V → (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ⊆ (𝐿 × V)) | 
| 31 |  | ssrin 4242 | . . . . . . 7
⊢ ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ⊆ (𝐿 × V) → ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) ⊆ ((𝐿 × V) ∩ (V × (𝑉 ↑m 𝑉)))) | 
| 32 | 29, 30, 31 | mp2b 10 | . . . . . 6
⊢ ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) ⊆ ((𝐿 × V) ∩ (V × (𝑉 ↑m 𝑉))) | 
| 33 |  | inxp 5842 | . . . . . 6
⊢ ((𝐿 × V) ∩ (V ×
(𝑉 ↑m 𝑉))) = ((𝐿 ∩ V) × (V ∩ (𝑉 ↑m 𝑉))) | 
| 34 | 32, 33 | sseqtri 4032 | . . . . 5
⊢ ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) ⊆ ((𝐿 ∩ V) × (V ∩ (𝑉 ↑m 𝑉))) | 
| 35 | 26, 34 | ssexi 5322 | . . . 4
⊢ ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) ∈ V | 
| 36 | 20, 21, 35 | fvmpt 7016 | . . 3
⊢ (𝑊 ∈ V →
(proj‘𝑊) = ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉)))) | 
| 37 |  | fvprc 6898 | . . . 4
⊢ (¬
𝑊 ∈ V →
(proj‘𝑊) =
∅) | 
| 38 |  | inss1 4237 | . . . . 5
⊢ ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) ⊆ (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) | 
| 39 |  | fvprc 6898 | . . . . . . . 8
⊢ (¬
𝑊 ∈ V →
(LSubSp‘𝑊) =
∅) | 
| 40 | 3, 39 | eqtrid 2789 | . . . . . . 7
⊢ (¬
𝑊 ∈ V → 𝐿 = ∅) | 
| 41 | 40 | mpteq1d 5237 | . . . . . 6
⊢ (¬
𝑊 ∈ V → (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) = (𝑥 ∈ ∅ ↦ (𝑥𝑃( ⊥ ‘𝑥)))) | 
| 42 |  | mpt0 6710 | . . . . . 6
⊢ (𝑥 ∈ ∅ ↦ (𝑥𝑃( ⊥ ‘𝑥))) = ∅ | 
| 43 | 41, 42 | eqtrdi 2793 | . . . . 5
⊢ (¬
𝑊 ∈ V → (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) = ∅) | 
| 44 |  | sseq0 4403 | . . . . 5
⊢ ((((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) ⊆ (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∧ (𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) = ∅) → ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) = ∅) | 
| 45 | 38, 43, 44 | sylancr 587 | . . . 4
⊢ (¬
𝑊 ∈ V → ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) = ∅) | 
| 46 | 37, 45 | eqtr4d 2780 | . . 3
⊢ (¬
𝑊 ∈ V →
(proj‘𝑊) = ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉)))) | 
| 47 | 36, 46 | pm2.61i 182 | . 2
⊢
(proj‘𝑊) =
((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) | 
| 48 | 1, 47 | eqtri 2765 | 1
⊢ 𝐾 = ((𝑥 ∈ 𝐿 ↦ (𝑥𝑃( ⊥ ‘𝑥))) ∩ (V × (𝑉 ↑m 𝑉))) |