| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | simp2 1138 | . . . . . . 7
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐼 ∧ 𝑦 ∈ 𝐽) → 𝑥 ∈ 𝐼) | 
| 2 |  | evlslem4.x | . . . . . . . 8
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐼) → 𝑋 ∈ 𝐵) | 
| 3 | 2 | 3adant3 1133 | . . . . . . 7
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐼 ∧ 𝑦 ∈ 𝐽) → 𝑋 ∈ 𝐵) | 
| 4 |  | eqid 2737 | . . . . . . . 8
⊢ (𝑥 ∈ 𝐼 ↦ 𝑋) = (𝑥 ∈ 𝐼 ↦ 𝑋) | 
| 5 | 4 | fvmpt2 7027 | . . . . . . 7
⊢ ((𝑥 ∈ 𝐼 ∧ 𝑋 ∈ 𝐵) → ((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) = 𝑋) | 
| 6 | 1, 3, 5 | syl2anc 584 | . . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐼 ∧ 𝑦 ∈ 𝐽) → ((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) = 𝑋) | 
| 7 |  | simp3 1139 | . . . . . . 7
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐼 ∧ 𝑦 ∈ 𝐽) → 𝑦 ∈ 𝐽) | 
| 8 |  | evlslem4.y | . . . . . . 7
⊢ ((𝜑 ∧ 𝑦 ∈ 𝐽) → 𝑌 ∈ 𝐵) | 
| 9 |  | eqid 2737 | . . . . . . . 8
⊢ (𝑦 ∈ 𝐽 ↦ 𝑌) = (𝑦 ∈ 𝐽 ↦ 𝑌) | 
| 10 | 9 | fvmpt2 7027 | . . . . . . 7
⊢ ((𝑦 ∈ 𝐽 ∧ 𝑌 ∈ 𝐵) → ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦) = 𝑌) | 
| 11 | 7, 8, 10 | 3imp3i2an 1346 | . . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐼 ∧ 𝑦 ∈ 𝐽) → ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦) = 𝑌) | 
| 12 | 6, 11 | oveq12d 7449 | . . . . 5
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐼 ∧ 𝑦 ∈ 𝐽) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦)) = (𝑋 · 𝑌)) | 
| 13 | 12 | mpoeq3dva 7510 | . . . 4
⊢ (𝜑 → (𝑥 ∈ 𝐼, 𝑦 ∈ 𝐽 ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦))) = (𝑥 ∈ 𝐼, 𝑦 ∈ 𝐽 ↦ (𝑋 · 𝑌))) | 
| 14 |  | nfcv 2905 | . . . . . 6
⊢
Ⅎ𝑖(((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦)) | 
| 15 |  | nfcv 2905 | . . . . . 6
⊢
Ⅎ𝑗(((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦)) | 
| 16 |  | nffvmpt1 6917 | . . . . . . 7
⊢
Ⅎ𝑥((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) | 
| 17 |  | nfcv 2905 | . . . . . . 7
⊢
Ⅎ𝑥
· | 
| 18 |  | nfcv 2905 | . . . . . . 7
⊢
Ⅎ𝑥((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗) | 
| 19 | 16, 17, 18 | nfov 7461 | . . . . . 6
⊢
Ⅎ𝑥(((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗)) | 
| 20 |  | nfcv 2905 | . . . . . . 7
⊢
Ⅎ𝑦((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) | 
| 21 |  | nfcv 2905 | . . . . . . 7
⊢
Ⅎ𝑦
· | 
| 22 |  | nffvmpt1 6917 | . . . . . . 7
⊢
Ⅎ𝑦((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗) | 
| 23 | 20, 21, 22 | nfov 7461 | . . . . . 6
⊢
Ⅎ𝑦(((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗)) | 
| 24 |  | fveq2 6906 | . . . . . . 7
⊢ (𝑥 = 𝑖 → ((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) = ((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖)) | 
| 25 |  | fveq2 6906 | . . . . . . 7
⊢ (𝑦 = 𝑗 → ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦) = ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗)) | 
| 26 | 24, 25 | oveqan12d 7450 | . . . . . 6
⊢ ((𝑥 = 𝑖 ∧ 𝑦 = 𝑗) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦)) = (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗))) | 
| 27 | 14, 15, 19, 23, 26 | cbvmpo 7527 | . . . . 5
⊢ (𝑥 ∈ 𝐼, 𝑦 ∈ 𝐽 ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦))) = (𝑖 ∈ 𝐼, 𝑗 ∈ 𝐽 ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗))) | 
| 28 |  | vex 3484 | . . . . . . . 8
⊢ 𝑖 ∈ V | 
| 29 |  | vex 3484 | . . . . . . . 8
⊢ 𝑗 ∈ V | 
| 30 | 28, 29 | eqop2 8057 | . . . . . . 7
⊢ (𝑧 = 〈𝑖, 𝑗〉 ↔ (𝑧 ∈ (V × V) ∧ ((1st
‘𝑧) = 𝑖 ∧ (2nd
‘𝑧) = 𝑗))) | 
| 31 |  | fveq2 6906 | . . . . . . . 8
⊢
((1st ‘𝑧) = 𝑖 → ((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) = ((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖)) | 
| 32 |  | fveq2 6906 | . . . . . . . 8
⊢
((2nd ‘𝑧) = 𝑗 → ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)) = ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗)) | 
| 33 | 31, 32 | oveqan12d 7450 | . . . . . . 7
⊢
(((1st ‘𝑧) = 𝑖 ∧ (2nd ‘𝑧) = 𝑗) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗))) | 
| 34 | 30, 33 | simplbiim 504 | . . . . . 6
⊢ (𝑧 = 〈𝑖, 𝑗〉 → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗))) | 
| 35 | 34 | mpompt 7547 | . . . . 5
⊢ (𝑧 ∈ (𝐼 × 𝐽) ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)))) = (𝑖 ∈ 𝐼, 𝑗 ∈ 𝐽 ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑖) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑗))) | 
| 36 | 27, 35 | eqtr4i 2768 | . . . 4
⊢ (𝑥 ∈ 𝐼, 𝑦 ∈ 𝐽 ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘𝑥) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘𝑦))) = (𝑧 ∈ (𝐼 × 𝐽) ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)))) | 
| 37 | 13, 36 | eqtr3di 2792 | . . 3
⊢ (𝜑 → (𝑥 ∈ 𝐼, 𝑦 ∈ 𝐽 ↦ (𝑋 · 𝑌)) = (𝑧 ∈ (𝐼 × 𝐽) ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))))) | 
| 38 | 37 | oveq1d 7446 | . 2
⊢ (𝜑 → ((𝑥 ∈ 𝐼, 𝑦 ∈ 𝐽 ↦ (𝑋 · 𝑌)) supp 0 ) = ((𝑧 ∈ (𝐼 × 𝐽) ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)))) supp 0 )) | 
| 39 |  | difxp 6184 | . . . . . 6
⊢ ((𝐼 × 𝐽) ∖ (((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ) × ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) = (((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽) ∪ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )))) | 
| 40 | 39 | eleq2i 2833 | . . . . 5
⊢ (𝑧 ∈ ((𝐼 × 𝐽) ∖ (((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ) × ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) ↔ 𝑧 ∈ (((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽) ∪ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))))) | 
| 41 |  | elun 4153 | . . . . 5
⊢ (𝑧 ∈ (((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽) ∪ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )))) ↔ (𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽) ∨ 𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))))) | 
| 42 | 40, 41 | bitri 275 | . . . 4
⊢ (𝑧 ∈ ((𝐼 × 𝐽) ∖ (((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ) × ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) ↔ (𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽) ∨ 𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))))) | 
| 43 |  | xp1st 8046 | . . . . . . . 8
⊢ (𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽) → (1st
‘𝑧) ∈ (𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ))) | 
| 44 | 2 | fmpttd 7135 | . . . . . . . . 9
⊢ (𝜑 → (𝑥 ∈ 𝐼 ↦ 𝑋):𝐼⟶𝐵) | 
| 45 |  | ssidd 4007 | . . . . . . . . 9
⊢ (𝜑 → ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ) ⊆ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) | 
| 46 |  | evlslem4.i | . . . . . . . . 9
⊢ (𝜑 → 𝐼 ∈ 𝑉) | 
| 47 |  | evlslem4.z | . . . . . . . . . . 11
⊢  0 =
(0g‘𝑅) | 
| 48 | 47 | fvexi 6920 | . . . . . . . . . 10
⊢  0 ∈
V | 
| 49 | 48 | a1i 11 | . . . . . . . . 9
⊢ (𝜑 → 0 ∈ V) | 
| 50 | 44, 45, 46, 49 | suppssr 8220 | . . . . . . . 8
⊢ ((𝜑 ∧ (1st
‘𝑧) ∈ (𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ))) → ((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) = 0 ) | 
| 51 | 43, 50 | sylan2 593 | . . . . . . 7
⊢ ((𝜑 ∧ 𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽)) → ((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) = 0 ) | 
| 52 | 51 | oveq1d 7446 | . . . . . 6
⊢ ((𝜑 ∧ 𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽)) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = ( 0 · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)))) | 
| 53 |  | evlslem4.r | . . . . . . 7
⊢ (𝜑 → 𝑅 ∈ Ring) | 
| 54 | 8 | fmpttd 7135 | . . . . . . . 8
⊢ (𝜑 → (𝑦 ∈ 𝐽 ↦ 𝑌):𝐽⟶𝐵) | 
| 55 |  | xp2nd 8047 | . . . . . . . 8
⊢ (𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽) → (2nd
‘𝑧) ∈ 𝐽) | 
| 56 |  | ffvelcdm 7101 | . . . . . . . 8
⊢ (((𝑦 ∈ 𝐽 ↦ 𝑌):𝐽⟶𝐵 ∧ (2nd ‘𝑧) ∈ 𝐽) → ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)) ∈ 𝐵) | 
| 57 | 54, 55, 56 | syl2an 596 | . . . . . . 7
⊢ ((𝜑 ∧ 𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽)) → ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)) ∈ 𝐵) | 
| 58 |  | evlslem4.b | . . . . . . . 8
⊢ 𝐵 = (Base‘𝑅) | 
| 59 |  | evlslem4.t | . . . . . . . 8
⊢  · =
(.r‘𝑅) | 
| 60 | 58, 59, 47 | ringlz 20290 | . . . . . . 7
⊢ ((𝑅 ∈ Ring ∧ ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)) ∈ 𝐵) → ( 0 · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = 0 ) | 
| 61 | 53, 57, 60 | syl2an2r 685 | . . . . . 6
⊢ ((𝜑 ∧ 𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽)) → ( 0 · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = 0 ) | 
| 62 | 52, 61 | eqtrd 2777 | . . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽)) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = 0 ) | 
| 63 |  | xp2nd 8047 | . . . . . . . 8
⊢ (𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) → (2nd
‘𝑧) ∈ (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) | 
| 64 |  | ssidd 4007 | . . . . . . . . 9
⊢ (𝜑 → ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ) ⊆ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )) | 
| 65 |  | evlslem4.j | . . . . . . . . 9
⊢ (𝜑 → 𝐽 ∈ 𝑊) | 
| 66 | 54, 64, 65, 49 | suppssr 8220 | . . . . . . . 8
⊢ ((𝜑 ∧ (2nd
‘𝑧) ∈ (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) → ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)) = 0 ) | 
| 67 | 63, 66 | sylan2 593 | . . . . . . 7
⊢ ((𝜑 ∧ 𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )))) → ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)) = 0 ) | 
| 68 | 67 | oveq2d 7447 | . . . . . 6
⊢ ((𝜑 ∧ 𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )))) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · 0 )) | 
| 69 |  | xp1st 8046 | . . . . . . . 8
⊢ (𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) → (1st
‘𝑧) ∈ 𝐼) | 
| 70 |  | ffvelcdm 7101 | . . . . . . . 8
⊢ (((𝑥 ∈ 𝐼 ↦ 𝑋):𝐼⟶𝐵 ∧ (1st ‘𝑧) ∈ 𝐼) → ((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) ∈ 𝐵) | 
| 71 | 44, 69, 70 | syl2an 596 | . . . . . . 7
⊢ ((𝜑 ∧ 𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )))) → ((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) ∈ 𝐵) | 
| 72 | 58, 59, 47 | ringrz 20291 | . . . . . . 7
⊢ ((𝑅 ∈ Ring ∧ ((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) ∈ 𝐵) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · 0 ) = 0 ) | 
| 73 | 53, 71, 72 | syl2an2r 685 | . . . . . 6
⊢ ((𝜑 ∧ 𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )))) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · 0 ) = 0 ) | 
| 74 | 68, 73 | eqtrd 2777 | . . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )))) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = 0 ) | 
| 75 | 62, 74 | jaodan 960 | . . . 4
⊢ ((𝜑 ∧ (𝑧 ∈ ((𝐼 ∖ ((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 )) × 𝐽) ∨ 𝑧 ∈ (𝐼 × (𝐽 ∖ ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))))) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = 0 ) | 
| 76 | 42, 75 | sylan2b 594 | . . 3
⊢ ((𝜑 ∧ 𝑧 ∈ ((𝐼 × 𝐽) ∖ (((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ) × ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 )))) → (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧))) = 0 ) | 
| 77 | 46, 65 | xpexd 7771 | . . 3
⊢ (𝜑 → (𝐼 × 𝐽) ∈ V) | 
| 78 | 76, 77 | suppss2 8225 | . 2
⊢ (𝜑 → ((𝑧 ∈ (𝐼 × 𝐽) ↦ (((𝑥 ∈ 𝐼 ↦ 𝑋)‘(1st ‘𝑧)) · ((𝑦 ∈ 𝐽 ↦ 𝑌)‘(2nd ‘𝑧)))) supp 0 ) ⊆ (((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ) × ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) | 
| 79 | 38, 78 | eqsstrd 4018 | 1
⊢ (𝜑 → ((𝑥 ∈ 𝐼, 𝑦 ∈ 𝐽 ↦ (𝑋 · 𝑌)) supp 0 ) ⊆ (((𝑥 ∈ 𝐼 ↦ 𝑋) supp 0 ) × ((𝑦 ∈ 𝐽 ↦ 𝑌) supp 0 ))) |