| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oppcco.b | ⊢ 𝐵  =  ( Base ‘ 𝐶 ) | 
						
							| 2 |  | oppcco.c | ⊢  ·   =  ( comp ‘ 𝐶 ) | 
						
							| 3 |  | oppcco.o | ⊢ 𝑂  =  ( oppCat ‘ 𝐶 ) | 
						
							| 4 |  | oppcco.x | ⊢ ( 𝜑  →  𝑋  ∈  𝐵 ) | 
						
							| 5 |  | oppcco.y | ⊢ ( 𝜑  →  𝑌  ∈  𝐵 ) | 
						
							| 6 |  | oppcco.z | ⊢ ( 𝜑  →  𝑍  ∈  𝐵 ) | 
						
							| 7 |  | elfvex | ⊢ ( 𝑋  ∈  ( Base ‘ 𝐶 )  →  𝐶  ∈  V ) | 
						
							| 8 | 7 1 | eleq2s | ⊢ ( 𝑋  ∈  𝐵  →  𝐶  ∈  V ) | 
						
							| 9 |  | eqid | ⊢ ( Hom  ‘ 𝐶 )  =  ( Hom  ‘ 𝐶 ) | 
						
							| 10 | 1 9 2 3 | oppcval | ⊢ ( 𝐶  ∈  V  →  𝑂  =  ( ( 𝐶  sSet  〈 ( Hom  ‘ ndx ) ,  tpos  ( Hom  ‘ 𝐶 ) 〉 )  sSet  〈 ( comp ‘ ndx ) ,  ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) ) 〉 ) ) | 
						
							| 11 | 4 8 10 | 3syl | ⊢ ( 𝜑  →  𝑂  =  ( ( 𝐶  sSet  〈 ( Hom  ‘ ndx ) ,  tpos  ( Hom  ‘ 𝐶 ) 〉 )  sSet  〈 ( comp ‘ ndx ) ,  ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) ) 〉 ) ) | 
						
							| 12 | 11 | fveq2d | ⊢ ( 𝜑  →  ( comp ‘ 𝑂 )  =  ( comp ‘ ( ( 𝐶  sSet  〈 ( Hom  ‘ ndx ) ,  tpos  ( Hom  ‘ 𝐶 ) 〉 )  sSet  〈 ( comp ‘ ndx ) ,  ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) ) 〉 ) ) ) | 
						
							| 13 |  | ovex | ⊢ ( 𝐶  sSet  〈 ( Hom  ‘ ndx ) ,  tpos  ( Hom  ‘ 𝐶 ) 〉 )  ∈  V | 
						
							| 14 | 1 | fvexi | ⊢ 𝐵  ∈  V | 
						
							| 15 | 14 14 | xpex | ⊢ ( 𝐵  ×  𝐵 )  ∈  V | 
						
							| 16 | 15 14 | mpoex | ⊢ ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) )  ∈  V | 
						
							| 17 |  | ccoid | ⊢ comp  =  Slot  ( comp ‘ ndx ) | 
						
							| 18 | 17 | setsid | ⊢ ( ( ( 𝐶  sSet  〈 ( Hom  ‘ ndx ) ,  tpos  ( Hom  ‘ 𝐶 ) 〉 )  ∈  V  ∧  ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) )  ∈  V )  →  ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) )  =  ( comp ‘ ( ( 𝐶  sSet  〈 ( Hom  ‘ ndx ) ,  tpos  ( Hom  ‘ 𝐶 ) 〉 )  sSet  〈 ( comp ‘ ndx ) ,  ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) ) 〉 ) ) ) | 
						
							| 19 | 13 16 18 | mp2an | ⊢ ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) )  =  ( comp ‘ ( ( 𝐶  sSet  〈 ( Hom  ‘ ndx ) ,  tpos  ( Hom  ‘ 𝐶 ) 〉 )  sSet  〈 ( comp ‘ ndx ) ,  ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) ) 〉 ) ) | 
						
							| 20 | 12 19 | eqtr4di | ⊢ ( 𝜑  →  ( comp ‘ 𝑂 )  =  ( 𝑢  ∈  ( 𝐵  ×  𝐵 ) ,  𝑧  ∈  𝐵  ↦  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) ) ) ) | 
						
							| 21 |  | simprr | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  𝑧  =  𝑍 ) | 
						
							| 22 |  | simprl | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  𝑢  =  〈 𝑋 ,  𝑌 〉 ) | 
						
							| 23 | 22 | fveq2d | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  ( 2nd  ‘ 𝑢 )  =  ( 2nd  ‘ 〈 𝑋 ,  𝑌 〉 ) ) | 
						
							| 24 | 5 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  𝑌  ∈  𝐵 ) | 
						
							| 25 |  | op2ndg | ⊢ ( ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  →  ( 2nd  ‘ 〈 𝑋 ,  𝑌 〉 )  =  𝑌 ) | 
						
							| 26 | 4 24 25 | syl2an2r | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  ( 2nd  ‘ 〈 𝑋 ,  𝑌 〉 )  =  𝑌 ) | 
						
							| 27 | 23 26 | eqtrd | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  ( 2nd  ‘ 𝑢 )  =  𝑌 ) | 
						
							| 28 | 21 27 | opeq12d | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  =  〈 𝑍 ,  𝑌 〉 ) | 
						
							| 29 | 22 | fveq2d | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  ( 1st  ‘ 𝑢 )  =  ( 1st  ‘ 〈 𝑋 ,  𝑌 〉 ) ) | 
						
							| 30 |  | op1stg | ⊢ ( ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  →  ( 1st  ‘ 〈 𝑋 ,  𝑌 〉 )  =  𝑋 ) | 
						
							| 31 | 4 24 30 | syl2an2r | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  ( 1st  ‘ 〈 𝑋 ,  𝑌 〉 )  =  𝑋 ) | 
						
							| 32 | 29 31 | eqtrd | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  ( 1st  ‘ 𝑢 )  =  𝑋 ) | 
						
							| 33 | 28 32 | oveq12d | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) )  =  ( 〈 𝑍 ,  𝑌 〉  ·  𝑋 ) ) | 
						
							| 34 | 33 | tposeqd | ⊢ ( ( 𝜑  ∧  ( 𝑢  =  〈 𝑋 ,  𝑌 〉  ∧  𝑧  =  𝑍 ) )  →  tpos  ( 〈 𝑧 ,  ( 2nd  ‘ 𝑢 ) 〉  ·  ( 1st  ‘ 𝑢 ) )  =  tpos  ( 〈 𝑍 ,  𝑌 〉  ·  𝑋 ) ) | 
						
							| 35 | 4 5 | opelxpd | ⊢ ( 𝜑  →  〈 𝑋 ,  𝑌 〉  ∈  ( 𝐵  ×  𝐵 ) ) | 
						
							| 36 |  | ovex | ⊢ ( 〈 𝑍 ,  𝑌 〉  ·  𝑋 )  ∈  V | 
						
							| 37 | 36 | tposex | ⊢ tpos  ( 〈 𝑍 ,  𝑌 〉  ·  𝑋 )  ∈  V | 
						
							| 38 | 37 | a1i | ⊢ ( 𝜑  →  tpos  ( 〈 𝑍 ,  𝑌 〉  ·  𝑋 )  ∈  V ) | 
						
							| 39 | 20 34 35 6 38 | ovmpod | ⊢ ( 𝜑  →  ( 〈 𝑋 ,  𝑌 〉 ( comp ‘ 𝑂 ) 𝑍 )  =  tpos  ( 〈 𝑍 ,  𝑌 〉  ·  𝑋 ) ) |