| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | isthincd2lem2.6 | . . . 4
⊢ (𝜑 → ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 ∀𝑓 ∈ (𝑥𝐻𝑦)∀𝑔 ∈ (𝑦𝐻𝑧)(𝑔(〈𝑥, 𝑦〉 · 𝑧)𝑓) ∈ (𝑥𝐻𝑧)) | 
| 2 |  | oveq1 7438 | . . . . . 6
⊢ (𝑥 = 𝑤 → (𝑥𝐻𝑦) = (𝑤𝐻𝑦)) | 
| 3 |  | opeq1 4873 | . . . . . . . . . 10
⊢ (𝑥 = 𝑤 → 〈𝑥, 𝑦〉 = 〈𝑤, 𝑦〉) | 
| 4 | 3 | oveq1d 7446 | . . . . . . . . 9
⊢ (𝑥 = 𝑤 → (〈𝑥, 𝑦〉 · 𝑧) = (〈𝑤, 𝑦〉 · 𝑧)) | 
| 5 | 4 | oveqd 7448 | . . . . . . . 8
⊢ (𝑥 = 𝑤 → (𝑔(〈𝑥, 𝑦〉 · 𝑧)𝑓) = (𝑔(〈𝑤, 𝑦〉 · 𝑧)𝑓)) | 
| 6 |  | oveq1 7438 | . . . . . . . 8
⊢ (𝑥 = 𝑤 → (𝑥𝐻𝑧) = (𝑤𝐻𝑧)) | 
| 7 | 5, 6 | eleq12d 2835 | . . . . . . 7
⊢ (𝑥 = 𝑤 → ((𝑔(〈𝑥, 𝑦〉 · 𝑧)𝑓) ∈ (𝑥𝐻𝑧) ↔ (𝑔(〈𝑤, 𝑦〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧))) | 
| 8 | 7 | ralbidv 3178 | . . . . . 6
⊢ (𝑥 = 𝑤 → (∀𝑔 ∈ (𝑦𝐻𝑧)(𝑔(〈𝑥, 𝑦〉 · 𝑧)𝑓) ∈ (𝑥𝐻𝑧) ↔ ∀𝑔 ∈ (𝑦𝐻𝑧)(𝑔(〈𝑤, 𝑦〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧))) | 
| 9 | 2, 8 | raleqbidv 3346 | . . . . 5
⊢ (𝑥 = 𝑤 → (∀𝑓 ∈ (𝑥𝐻𝑦)∀𝑔 ∈ (𝑦𝐻𝑧)(𝑔(〈𝑥, 𝑦〉 · 𝑧)𝑓) ∈ (𝑥𝐻𝑧) ↔ ∀𝑓 ∈ (𝑤𝐻𝑦)∀𝑔 ∈ (𝑦𝐻𝑧)(𝑔(〈𝑤, 𝑦〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧))) | 
| 10 |  | oveq2 7439 | . . . . . 6
⊢ (𝑦 = 𝑣 → (𝑤𝐻𝑦) = (𝑤𝐻𝑣)) | 
| 11 |  | oveq1 7438 | . . . . . . 7
⊢ (𝑦 = 𝑣 → (𝑦𝐻𝑧) = (𝑣𝐻𝑧)) | 
| 12 |  | opeq2 4874 | . . . . . . . . . 10
⊢ (𝑦 = 𝑣 → 〈𝑤, 𝑦〉 = 〈𝑤, 𝑣〉) | 
| 13 | 12 | oveq1d 7446 | . . . . . . . . 9
⊢ (𝑦 = 𝑣 → (〈𝑤, 𝑦〉 · 𝑧) = (〈𝑤, 𝑣〉 · 𝑧)) | 
| 14 | 13 | oveqd 7448 | . . . . . . . 8
⊢ (𝑦 = 𝑣 → (𝑔(〈𝑤, 𝑦〉 · 𝑧)𝑓) = (𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓)) | 
| 15 | 14 | eleq1d 2826 | . . . . . . 7
⊢ (𝑦 = 𝑣 → ((𝑔(〈𝑤, 𝑦〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧) ↔ (𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧))) | 
| 16 | 11, 15 | raleqbidv 3346 | . . . . . 6
⊢ (𝑦 = 𝑣 → (∀𝑔 ∈ (𝑦𝐻𝑧)(𝑔(〈𝑤, 𝑦〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧) ↔ ∀𝑔 ∈ (𝑣𝐻𝑧)(𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧))) | 
| 17 | 10, 16 | raleqbidv 3346 | . . . . 5
⊢ (𝑦 = 𝑣 → (∀𝑓 ∈ (𝑤𝐻𝑦)∀𝑔 ∈ (𝑦𝐻𝑧)(𝑔(〈𝑤, 𝑦〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧) ↔ ∀𝑓 ∈ (𝑤𝐻𝑣)∀𝑔 ∈ (𝑣𝐻𝑧)(𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧))) | 
| 18 |  | oveq2 7439 | . . . . . . . 8
⊢ (𝑧 = 𝑢 → (𝑣𝐻𝑧) = (𝑣𝐻𝑢)) | 
| 19 |  | oveq2 7439 | . . . . . . . . . 10
⊢ (𝑧 = 𝑢 → (〈𝑤, 𝑣〉 · 𝑧) = (〈𝑤, 𝑣〉 · 𝑢)) | 
| 20 | 19 | oveqd 7448 | . . . . . . . . 9
⊢ (𝑧 = 𝑢 → (𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓) = (𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑓)) | 
| 21 |  | oveq2 7439 | . . . . . . . . 9
⊢ (𝑧 = 𝑢 → (𝑤𝐻𝑧) = (𝑤𝐻𝑢)) | 
| 22 | 20, 21 | eleq12d 2835 | . . . . . . . 8
⊢ (𝑧 = 𝑢 → ((𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧) ↔ (𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑓) ∈ (𝑤𝐻𝑢))) | 
| 23 | 18, 22 | raleqbidv 3346 | . . . . . . 7
⊢ (𝑧 = 𝑢 → (∀𝑔 ∈ (𝑣𝐻𝑧)(𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧) ↔ ∀𝑔 ∈ (𝑣𝐻𝑢)(𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑓) ∈ (𝑤𝐻𝑢))) | 
| 24 | 23 | ralbidv 3178 | . . . . . 6
⊢ (𝑧 = 𝑢 → (∀𝑓 ∈ (𝑤𝐻𝑣)∀𝑔 ∈ (𝑣𝐻𝑧)(𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧) ↔ ∀𝑓 ∈ (𝑤𝐻𝑣)∀𝑔 ∈ (𝑣𝐻𝑢)(𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑓) ∈ (𝑤𝐻𝑢))) | 
| 25 |  | oveq2 7439 | . . . . . . . 8
⊢ (𝑓 = 𝑘 → (𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑓) = (𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑘)) | 
| 26 | 25 | eleq1d 2826 | . . . . . . 7
⊢ (𝑓 = 𝑘 → ((𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑓) ∈ (𝑤𝐻𝑢) ↔ (𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢))) | 
| 27 |  | oveq1 7438 | . . . . . . . 8
⊢ (𝑔 = 𝑙 → (𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑘) = (𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘)) | 
| 28 | 27 | eleq1d 2826 | . . . . . . 7
⊢ (𝑔 = 𝑙 → ((𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢) ↔ (𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢))) | 
| 29 | 26, 28 | cbvral2vw 3241 | . . . . . 6
⊢
(∀𝑓 ∈
(𝑤𝐻𝑣)∀𝑔 ∈ (𝑣𝐻𝑢)(𝑔(〈𝑤, 𝑣〉 · 𝑢)𝑓) ∈ (𝑤𝐻𝑢) ↔ ∀𝑘 ∈ (𝑤𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢)) | 
| 30 | 24, 29 | bitrdi 287 | . . . . 5
⊢ (𝑧 = 𝑢 → (∀𝑓 ∈ (𝑤𝐻𝑣)∀𝑔 ∈ (𝑣𝐻𝑧)(𝑔(〈𝑤, 𝑣〉 · 𝑧)𝑓) ∈ (𝑤𝐻𝑧) ↔ ∀𝑘 ∈ (𝑤𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢))) | 
| 31 | 9, 17, 30 | cbvral3vw 3243 | . . . 4
⊢
(∀𝑥 ∈
𝐵 ∀𝑦 ∈ 𝐵 ∀𝑧 ∈ 𝐵 ∀𝑓 ∈ (𝑥𝐻𝑦)∀𝑔 ∈ (𝑦𝐻𝑧)(𝑔(〈𝑥, 𝑦〉 · 𝑧)𝑓) ∈ (𝑥𝐻𝑧) ↔ ∀𝑤 ∈ 𝐵 ∀𝑣 ∈ 𝐵 ∀𝑢 ∈ 𝐵 ∀𝑘 ∈ (𝑤𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢)) | 
| 32 | 1, 31 | sylib 218 | . . 3
⊢ (𝜑 → ∀𝑤 ∈ 𝐵 ∀𝑣 ∈ 𝐵 ∀𝑢 ∈ 𝐵 ∀𝑘 ∈ (𝑤𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢)) | 
| 33 |  | isthincd2lem2.1 | . . . 4
⊢ (𝜑 → 𝑋 ∈ 𝐵) | 
| 34 |  | isthincd2lem2.2 | . . . 4
⊢ (𝜑 → 𝑌 ∈ 𝐵) | 
| 35 |  | isthincd2lem2.3 | . . . 4
⊢ (𝜑 → 𝑍 ∈ 𝐵) | 
| 36 |  | oveq1 7438 | . . . . . 6
⊢ (𝑤 = 𝑋 → (𝑤𝐻𝑣) = (𝑋𝐻𝑣)) | 
| 37 |  | opeq1 4873 | . . . . . . . . . 10
⊢ (𝑤 = 𝑋 → 〈𝑤, 𝑣〉 = 〈𝑋, 𝑣〉) | 
| 38 | 37 | oveq1d 7446 | . . . . . . . . 9
⊢ (𝑤 = 𝑋 → (〈𝑤, 𝑣〉 · 𝑢) = (〈𝑋, 𝑣〉 · 𝑢)) | 
| 39 | 38 | oveqd 7448 | . . . . . . . 8
⊢ (𝑤 = 𝑋 → (𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) = (𝑙(〈𝑋, 𝑣〉 · 𝑢)𝑘)) | 
| 40 |  | oveq1 7438 | . . . . . . . 8
⊢ (𝑤 = 𝑋 → (𝑤𝐻𝑢) = (𝑋𝐻𝑢)) | 
| 41 | 39, 40 | eleq12d 2835 | . . . . . . 7
⊢ (𝑤 = 𝑋 → ((𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢) ↔ (𝑙(〈𝑋, 𝑣〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢))) | 
| 42 | 41 | ralbidv 3178 | . . . . . 6
⊢ (𝑤 = 𝑋 → (∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢) ↔ ∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑋, 𝑣〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢))) | 
| 43 | 36, 42 | raleqbidv 3346 | . . . . 5
⊢ (𝑤 = 𝑋 → (∀𝑘 ∈ (𝑤𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢) ↔ ∀𝑘 ∈ (𝑋𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑋, 𝑣〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢))) | 
| 44 |  | oveq2 7439 | . . . . . 6
⊢ (𝑣 = 𝑌 → (𝑋𝐻𝑣) = (𝑋𝐻𝑌)) | 
| 45 |  | oveq1 7438 | . . . . . . 7
⊢ (𝑣 = 𝑌 → (𝑣𝐻𝑢) = (𝑌𝐻𝑢)) | 
| 46 |  | opeq2 4874 | . . . . . . . . . 10
⊢ (𝑣 = 𝑌 → 〈𝑋, 𝑣〉 = 〈𝑋, 𝑌〉) | 
| 47 | 46 | oveq1d 7446 | . . . . . . . . 9
⊢ (𝑣 = 𝑌 → (〈𝑋, 𝑣〉 · 𝑢) = (〈𝑋, 𝑌〉 · 𝑢)) | 
| 48 | 47 | oveqd 7448 | . . . . . . . 8
⊢ (𝑣 = 𝑌 → (𝑙(〈𝑋, 𝑣〉 · 𝑢)𝑘) = (𝑙(〈𝑋, 𝑌〉 · 𝑢)𝑘)) | 
| 49 | 48 | eleq1d 2826 | . . . . . . 7
⊢ (𝑣 = 𝑌 → ((𝑙(〈𝑋, 𝑣〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢) ↔ (𝑙(〈𝑋, 𝑌〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢))) | 
| 50 | 45, 49 | raleqbidv 3346 | . . . . . 6
⊢ (𝑣 = 𝑌 → (∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑋, 𝑣〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢) ↔ ∀𝑙 ∈ (𝑌𝐻𝑢)(𝑙(〈𝑋, 𝑌〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢))) | 
| 51 | 44, 50 | raleqbidv 3346 | . . . . 5
⊢ (𝑣 = 𝑌 → (∀𝑘 ∈ (𝑋𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑋, 𝑣〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢) ↔ ∀𝑘 ∈ (𝑋𝐻𝑌)∀𝑙 ∈ (𝑌𝐻𝑢)(𝑙(〈𝑋, 𝑌〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢))) | 
| 52 |  | oveq2 7439 | . . . . . . 7
⊢ (𝑢 = 𝑍 → (𝑌𝐻𝑢) = (𝑌𝐻𝑍)) | 
| 53 |  | oveq2 7439 | . . . . . . . . 9
⊢ (𝑢 = 𝑍 → (〈𝑋, 𝑌〉 · 𝑢) = (〈𝑋, 𝑌〉 · 𝑍)) | 
| 54 | 53 | oveqd 7448 | . . . . . . . 8
⊢ (𝑢 = 𝑍 → (𝑙(〈𝑋, 𝑌〉 · 𝑢)𝑘) = (𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘)) | 
| 55 |  | oveq2 7439 | . . . . . . . 8
⊢ (𝑢 = 𝑍 → (𝑋𝐻𝑢) = (𝑋𝐻𝑍)) | 
| 56 | 54, 55 | eleq12d 2835 | . . . . . . 7
⊢ (𝑢 = 𝑍 → ((𝑙(〈𝑋, 𝑌〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢) ↔ (𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍))) | 
| 57 | 52, 56 | raleqbidv 3346 | . . . . . 6
⊢ (𝑢 = 𝑍 → (∀𝑙 ∈ (𝑌𝐻𝑢)(𝑙(〈𝑋, 𝑌〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢) ↔ ∀𝑙 ∈ (𝑌𝐻𝑍)(𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍))) | 
| 58 | 57 | ralbidv 3178 | . . . . 5
⊢ (𝑢 = 𝑍 → (∀𝑘 ∈ (𝑋𝐻𝑌)∀𝑙 ∈ (𝑌𝐻𝑢)(𝑙(〈𝑋, 𝑌〉 · 𝑢)𝑘) ∈ (𝑋𝐻𝑢) ↔ ∀𝑘 ∈ (𝑋𝐻𝑌)∀𝑙 ∈ (𝑌𝐻𝑍)(𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍))) | 
| 59 | 43, 51, 58 | rspc3v 3638 | . . . 4
⊢ ((𝑋 ∈ 𝐵 ∧ 𝑌 ∈ 𝐵 ∧ 𝑍 ∈ 𝐵) → (∀𝑤 ∈ 𝐵 ∀𝑣 ∈ 𝐵 ∀𝑢 ∈ 𝐵 ∀𝑘 ∈ (𝑤𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢) → ∀𝑘 ∈ (𝑋𝐻𝑌)∀𝑙 ∈ (𝑌𝐻𝑍)(𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍))) | 
| 60 | 33, 34, 35, 59 | syl3anc 1373 | . . 3
⊢ (𝜑 → (∀𝑤 ∈ 𝐵 ∀𝑣 ∈ 𝐵 ∀𝑢 ∈ 𝐵 ∀𝑘 ∈ (𝑤𝐻𝑣)∀𝑙 ∈ (𝑣𝐻𝑢)(𝑙(〈𝑤, 𝑣〉 · 𝑢)𝑘) ∈ (𝑤𝐻𝑢) → ∀𝑘 ∈ (𝑋𝐻𝑌)∀𝑙 ∈ (𝑌𝐻𝑍)(𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍))) | 
| 61 | 32, 60 | mpd 15 | . 2
⊢ (𝜑 → ∀𝑘 ∈ (𝑋𝐻𝑌)∀𝑙 ∈ (𝑌𝐻𝑍)(𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍)) | 
| 62 |  | isthincd2lem2.4 | . . 3
⊢ (𝜑 → 𝐹 ∈ (𝑋𝐻𝑌)) | 
| 63 |  | isthincd2lem2.5 | . . 3
⊢ (𝜑 → 𝐺 ∈ (𝑌𝐻𝑍)) | 
| 64 |  | oveq2 7439 | . . . . 5
⊢ (𝑘 = 𝐹 → (𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) = (𝑙(〈𝑋, 𝑌〉 · 𝑍)𝐹)) | 
| 65 | 64 | eleq1d 2826 | . . . 4
⊢ (𝑘 = 𝐹 → ((𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍) ↔ (𝑙(〈𝑋, 𝑌〉 · 𝑍)𝐹) ∈ (𝑋𝐻𝑍))) | 
| 66 |  | oveq1 7438 | . . . . 5
⊢ (𝑙 = 𝐺 → (𝑙(〈𝑋, 𝑌〉 · 𝑍)𝐹) = (𝐺(〈𝑋, 𝑌〉 · 𝑍)𝐹)) | 
| 67 | 66 | eleq1d 2826 | . . . 4
⊢ (𝑙 = 𝐺 → ((𝑙(〈𝑋, 𝑌〉 · 𝑍)𝐹) ∈ (𝑋𝐻𝑍) ↔ (𝐺(〈𝑋, 𝑌〉 · 𝑍)𝐹) ∈ (𝑋𝐻𝑍))) | 
| 68 | 65, 67 | rspc2v 3633 | . . 3
⊢ ((𝐹 ∈ (𝑋𝐻𝑌) ∧ 𝐺 ∈ (𝑌𝐻𝑍)) → (∀𝑘 ∈ (𝑋𝐻𝑌)∀𝑙 ∈ (𝑌𝐻𝑍)(𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍) → (𝐺(〈𝑋, 𝑌〉 · 𝑍)𝐹) ∈ (𝑋𝐻𝑍))) | 
| 69 | 62, 63, 68 | syl2anc 584 | . 2
⊢ (𝜑 → (∀𝑘 ∈ (𝑋𝐻𝑌)∀𝑙 ∈ (𝑌𝐻𝑍)(𝑙(〈𝑋, 𝑌〉 · 𝑍)𝑘) ∈ (𝑋𝐻𝑍) → (𝐺(〈𝑋, 𝑌〉 · 𝑍)𝐹) ∈ (𝑋𝐻𝑍))) | 
| 70 | 61, 69 | mpd 15 | 1
⊢ (𝜑 → (𝐺(〈𝑋, 𝑌〉 · 𝑍)𝐹) ∈ (𝑋𝐻𝑍)) |