| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isthincd2lem2.1 | ⊢ ( 𝜑  →  𝑋  ∈  𝐵 ) | 
						
							| 2 |  | isthincd2lem2.2 | ⊢ ( 𝜑  →  𝑌  ∈  𝐵 ) | 
						
							| 3 |  | isthincd2lem2.3 | ⊢ ( 𝜑  →  𝑍  ∈  𝐵 ) | 
						
							| 4 |  | isthincd2lem2.4 | ⊢ ( 𝜑  →  𝐹  ∈  ( 𝑋 𝐻 𝑌 ) ) | 
						
							| 5 |  | isthincd2lem2.5 | ⊢ ( 𝜑  →  𝐺  ∈  ( 𝑌 𝐻 𝑍 ) ) | 
						
							| 6 |  | isthincd2lem2.6 | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ∀ 𝑧  ∈  𝐵 ∀ 𝑓  ∈  ( 𝑥 𝐻 𝑦 ) ∀ 𝑔  ∈  ( 𝑦 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑥 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑥 𝐻 𝑧 ) ) | 
						
							| 7 |  | oveq1 | ⊢ ( 𝑥  =  𝑤  →  ( 𝑥 𝐻 𝑦 )  =  ( 𝑤 𝐻 𝑦 ) ) | 
						
							| 8 |  | opeq1 | ⊢ ( 𝑥  =  𝑤  →  〈 𝑥 ,  𝑦 〉  =  〈 𝑤 ,  𝑦 〉 ) | 
						
							| 9 | 8 | oveq1d | ⊢ ( 𝑥  =  𝑤  →  ( 〈 𝑥 ,  𝑦 〉  ·  𝑧 )  =  ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) ) | 
						
							| 10 | 9 | oveqd | ⊢ ( 𝑥  =  𝑤  →  ( 𝑔 ( 〈 𝑥 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  =  ( 𝑔 ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) 𝑓 ) ) | 
						
							| 11 |  | oveq1 | ⊢ ( 𝑥  =  𝑤  →  ( 𝑥 𝐻 𝑧 )  =  ( 𝑤 𝐻 𝑧 ) ) | 
						
							| 12 | 10 11 | eleq12d | ⊢ ( 𝑥  =  𝑤  →  ( ( 𝑔 ( 〈 𝑥 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑥 𝐻 𝑧 )  ↔  ( 𝑔 ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 ) ) ) | 
						
							| 13 | 12 | ralbidv | ⊢ ( 𝑥  =  𝑤  →  ( ∀ 𝑔  ∈  ( 𝑦 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑥 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑥 𝐻 𝑧 )  ↔  ∀ 𝑔  ∈  ( 𝑦 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 ) ) ) | 
						
							| 14 | 7 13 | raleqbidv | ⊢ ( 𝑥  =  𝑤  →  ( ∀ 𝑓  ∈  ( 𝑥 𝐻 𝑦 ) ∀ 𝑔  ∈  ( 𝑦 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑥 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑥 𝐻 𝑧 )  ↔  ∀ 𝑓  ∈  ( 𝑤 𝐻 𝑦 ) ∀ 𝑔  ∈  ( 𝑦 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 ) ) ) | 
						
							| 15 |  | oveq2 | ⊢ ( 𝑦  =  𝑣  →  ( 𝑤 𝐻 𝑦 )  =  ( 𝑤 𝐻 𝑣 ) ) | 
						
							| 16 |  | oveq1 | ⊢ ( 𝑦  =  𝑣  →  ( 𝑦 𝐻 𝑧 )  =  ( 𝑣 𝐻 𝑧 ) ) | 
						
							| 17 |  | opeq2 | ⊢ ( 𝑦  =  𝑣  →  〈 𝑤 ,  𝑦 〉  =  〈 𝑤 ,  𝑣 〉 ) | 
						
							| 18 | 17 | oveq1d | ⊢ ( 𝑦  =  𝑣  →  ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 )  =  ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) ) | 
						
							| 19 | 18 | oveqd | ⊢ ( 𝑦  =  𝑣  →  ( 𝑔 ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  =  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 ) ) | 
						
							| 20 | 19 | eleq1d | ⊢ ( 𝑦  =  𝑣  →  ( ( 𝑔 ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 )  ↔  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 ) ) ) | 
						
							| 21 | 16 20 | raleqbidv | ⊢ ( 𝑦  =  𝑣  →  ( ∀ 𝑔  ∈  ( 𝑦 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 )  ↔  ∀ 𝑔  ∈  ( 𝑣 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 ) ) ) | 
						
							| 22 | 15 21 | raleqbidv | ⊢ ( 𝑦  =  𝑣  →  ( ∀ 𝑓  ∈  ( 𝑤 𝐻 𝑦 ) ∀ 𝑔  ∈  ( 𝑦 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 )  ↔  ∀ 𝑓  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑔  ∈  ( 𝑣 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 ) ) ) | 
						
							| 23 |  | oveq2 | ⊢ ( 𝑧  =  𝑢  →  ( 𝑣 𝐻 𝑧 )  =  ( 𝑣 𝐻 𝑢 ) ) | 
						
							| 24 |  | oveq2 | ⊢ ( 𝑧  =  𝑢  →  ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 )  =  ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) ) | 
						
							| 25 | 24 | oveqd | ⊢ ( 𝑧  =  𝑢  →  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 )  =  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑓 ) ) | 
						
							| 26 |  | oveq2 | ⊢ ( 𝑧  =  𝑢  →  ( 𝑤 𝐻 𝑧 )  =  ( 𝑤 𝐻 𝑢 ) ) | 
						
							| 27 | 25 26 | eleq12d | ⊢ ( 𝑧  =  𝑢  →  ( ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 )  ↔  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑢 ) ) ) | 
						
							| 28 | 23 27 | raleqbidv | ⊢ ( 𝑧  =  𝑢  →  ( ∀ 𝑔  ∈  ( 𝑣 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 )  ↔  ∀ 𝑔  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑢 ) ) ) | 
						
							| 29 | 28 | ralbidv | ⊢ ( 𝑧  =  𝑢  →  ( ∀ 𝑓  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑔  ∈  ( 𝑣 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 )  ↔  ∀ 𝑓  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑔  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑢 ) ) ) | 
						
							| 30 |  | oveq2 | ⊢ ( 𝑓  =  𝑘  →  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑓 )  =  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 ) ) | 
						
							| 31 | 30 | eleq1d | ⊢ ( 𝑓  =  𝑘  →  ( ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑢 )  ↔  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 ) ) ) | 
						
							| 32 |  | oveq1 | ⊢ ( 𝑔  =  𝑙  →  ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  =  ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 ) ) | 
						
							| 33 | 32 | eleq1d | ⊢ ( 𝑔  =  𝑙  →  ( ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 )  ↔  ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 ) ) ) | 
						
							| 34 | 31 33 | cbvral2vw | ⊢ ( ∀ 𝑓  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑔  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑢 )  ↔  ∀ 𝑘  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 ) ) | 
						
							| 35 | 29 34 | bitrdi | ⊢ ( 𝑧  =  𝑢  →  ( ∀ 𝑓  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑔  ∈  ( 𝑣 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑤 ,  𝑣 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑤 𝐻 𝑧 )  ↔  ∀ 𝑘  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 ) ) ) | 
						
							| 36 | 14 22 35 | cbvral3vw | ⊢ ( ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ∀ 𝑧  ∈  𝐵 ∀ 𝑓  ∈  ( 𝑥 𝐻 𝑦 ) ∀ 𝑔  ∈  ( 𝑦 𝐻 𝑧 ) ( 𝑔 ( 〈 𝑥 ,  𝑦 〉  ·  𝑧 ) 𝑓 )  ∈  ( 𝑥 𝐻 𝑧 )  ↔  ∀ 𝑤  ∈  𝐵 ∀ 𝑣  ∈  𝐵 ∀ 𝑢  ∈  𝐵 ∀ 𝑘  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 ) ) | 
						
							| 37 | 6 36 | sylib | ⊢ ( 𝜑  →  ∀ 𝑤  ∈  𝐵 ∀ 𝑣  ∈  𝐵 ∀ 𝑢  ∈  𝐵 ∀ 𝑘  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 ) ) | 
						
							| 38 |  | oveq1 | ⊢ ( 𝑤  =  𝑋  →  ( 𝑤 𝐻 𝑣 )  =  ( 𝑋 𝐻 𝑣 ) ) | 
						
							| 39 |  | opeq1 | ⊢ ( 𝑤  =  𝑋  →  〈 𝑤 ,  𝑣 〉  =  〈 𝑋 ,  𝑣 〉 ) | 
						
							| 40 | 39 | oveq1d | ⊢ ( 𝑤  =  𝑋  →  ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 )  =  ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) ) | 
						
							| 41 | 40 | oveqd | ⊢ ( 𝑤  =  𝑋  →  ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  =  ( 𝑙 ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) 𝑘 ) ) | 
						
							| 42 |  | oveq1 | ⊢ ( 𝑤  =  𝑋  →  ( 𝑤 𝐻 𝑢 )  =  ( 𝑋 𝐻 𝑢 ) ) | 
						
							| 43 | 41 42 | eleq12d | ⊢ ( 𝑤  =  𝑋  →  ( ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 )  ↔  ( 𝑙 ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 ) ) ) | 
						
							| 44 | 43 | ralbidv | ⊢ ( 𝑤  =  𝑋  →  ( ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 )  ↔  ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 ) ) ) | 
						
							| 45 | 38 44 | raleqbidv | ⊢ ( 𝑤  =  𝑋  →  ( ∀ 𝑘  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 )  ↔  ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 ) ) ) | 
						
							| 46 |  | oveq2 | ⊢ ( 𝑣  =  𝑌  →  ( 𝑋 𝐻 𝑣 )  =  ( 𝑋 𝐻 𝑌 ) ) | 
						
							| 47 |  | oveq1 | ⊢ ( 𝑣  =  𝑌  →  ( 𝑣 𝐻 𝑢 )  =  ( 𝑌 𝐻 𝑢 ) ) | 
						
							| 48 |  | opeq2 | ⊢ ( 𝑣  =  𝑌  →  〈 𝑋 ,  𝑣 〉  =  〈 𝑋 ,  𝑌 〉 ) | 
						
							| 49 | 48 | oveq1d | ⊢ ( 𝑣  =  𝑌  →  ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 )  =  ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) ) | 
						
							| 50 | 49 | oveqd | ⊢ ( 𝑣  =  𝑌  →  ( 𝑙 ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  =  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) 𝑘 ) ) | 
						
							| 51 | 50 | eleq1d | ⊢ ( 𝑣  =  𝑌  →  ( ( 𝑙 ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 )  ↔  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 ) ) ) | 
						
							| 52 | 47 51 | raleqbidv | ⊢ ( 𝑣  =  𝑌  →  ( ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 )  ↔  ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 ) ) ) | 
						
							| 53 | 46 52 | raleqbidv | ⊢ ( 𝑣  =  𝑌  →  ( ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑋 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 )  ↔  ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑌 ) ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 ) ) ) | 
						
							| 54 |  | oveq2 | ⊢ ( 𝑢  =  𝑍  →  ( 𝑌 𝐻 𝑢 )  =  ( 𝑌 𝐻 𝑍 ) ) | 
						
							| 55 |  | oveq2 | ⊢ ( 𝑢  =  𝑍  →  ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 )  =  ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) ) | 
						
							| 56 | 55 | oveqd | ⊢ ( 𝑢  =  𝑍  →  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) 𝑘 )  =  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 ) ) | 
						
							| 57 |  | oveq2 | ⊢ ( 𝑢  =  𝑍  →  ( 𝑋 𝐻 𝑢 )  =  ( 𝑋 𝐻 𝑍 ) ) | 
						
							| 58 | 56 57 | eleq12d | ⊢ ( 𝑢  =  𝑍  →  ( ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 )  ↔  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 59 | 54 58 | raleqbidv | ⊢ ( 𝑢  =  𝑍  →  ( ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 )  ↔  ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑍 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 60 | 59 | ralbidv | ⊢ ( 𝑢  =  𝑍  →  ( ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑌 ) ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑢 )  ↔  ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑌 ) ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑍 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 61 | 45 53 60 | rspc3v | ⊢ ( ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  →  ( ∀ 𝑤  ∈  𝐵 ∀ 𝑣  ∈  𝐵 ∀ 𝑢  ∈  𝐵 ∀ 𝑘  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 )  →  ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑌 ) ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑍 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 62 | 1 2 3 61 | syl3anc | ⊢ ( 𝜑  →  ( ∀ 𝑤  ∈  𝐵 ∀ 𝑣  ∈  𝐵 ∀ 𝑢  ∈  𝐵 ∀ 𝑘  ∈  ( 𝑤 𝐻 𝑣 ) ∀ 𝑙  ∈  ( 𝑣 𝐻 𝑢 ) ( 𝑙 ( 〈 𝑤 ,  𝑣 〉  ·  𝑢 ) 𝑘 )  ∈  ( 𝑤 𝐻 𝑢 )  →  ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑌 ) ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑍 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 63 | 37 62 | mpd | ⊢ ( 𝜑  →  ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑌 ) ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑍 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 ) ) | 
						
							| 64 |  | oveq2 | ⊢ ( 𝑘  =  𝐹  →  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  =  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 ) ) | 
						
							| 65 | 64 | eleq1d | ⊢ ( 𝑘  =  𝐹  →  ( ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 )  ↔  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 66 |  | oveq1 | ⊢ ( 𝑙  =  𝐺  →  ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 )  =  ( 𝐺 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 ) ) | 
						
							| 67 | 66 | eleq1d | ⊢ ( 𝑙  =  𝐺  →  ( ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 )  ∈  ( 𝑋 𝐻 𝑍 )  ↔  ( 𝐺 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 68 | 65 67 | rspc2v | ⊢ ( ( 𝐹  ∈  ( 𝑋 𝐻 𝑌 )  ∧  𝐺  ∈  ( 𝑌 𝐻 𝑍 ) )  →  ( ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑌 ) ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑍 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 )  →  ( 𝐺 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 69 | 4 5 68 | syl2anc | ⊢ ( 𝜑  →  ( ∀ 𝑘  ∈  ( 𝑋 𝐻 𝑌 ) ∀ 𝑙  ∈  ( 𝑌 𝐻 𝑍 ) ( 𝑙 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝑘 )  ∈  ( 𝑋 𝐻 𝑍 )  →  ( 𝐺 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 )  ∈  ( 𝑋 𝐻 𝑍 ) ) ) | 
						
							| 70 | 63 69 | mpd | ⊢ ( 𝜑  →  ( 𝐺 ( 〈 𝑋 ,  𝑌 〉  ·  𝑍 ) 𝐹 )  ∈  ( 𝑋 𝐻 𝑍 ) ) |