| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 3optocl.1 | ⊢ 𝑅  =  ( 𝐷  ×  𝐹 ) | 
						
							| 2 |  | 3optocl.2 | ⊢ ( 〈 𝑥 ,  𝑦 〉  =  𝐴  →  ( 𝜑  ↔  𝜓 ) ) | 
						
							| 3 |  | 3optocl.3 | ⊢ ( 〈 𝑧 ,  𝑤 〉  =  𝐵  →  ( 𝜓  ↔  𝜒 ) ) | 
						
							| 4 |  | 3optocl.4 | ⊢ ( 〈 𝑣 ,  𝑢 〉  =  𝐶  →  ( 𝜒  ↔  𝜃 ) ) | 
						
							| 5 |  | 3optocl.5 | ⊢ ( ( ( 𝑥  ∈  𝐷  ∧  𝑦  ∈  𝐹 )  ∧  ( 𝑧  ∈  𝐷  ∧  𝑤  ∈  𝐹 )  ∧  ( 𝑣  ∈  𝐷  ∧  𝑢  ∈  𝐹 ) )  →  𝜑 ) | 
						
							| 6 | 4 | imbi2d | ⊢ ( 〈 𝑣 ,  𝑢 〉  =  𝐶  →  ( ( ( 𝐴  ∈  𝑅  ∧  𝐵  ∈  𝑅 )  →  𝜒 )  ↔  ( ( 𝐴  ∈  𝑅  ∧  𝐵  ∈  𝑅 )  →  𝜃 ) ) ) | 
						
							| 7 | 2 | imbi2d | ⊢ ( 〈 𝑥 ,  𝑦 〉  =  𝐴  →  ( ( ( 𝑣  ∈  𝐷  ∧  𝑢  ∈  𝐹 )  →  𝜑 )  ↔  ( ( 𝑣  ∈  𝐷  ∧  𝑢  ∈  𝐹 )  →  𝜓 ) ) ) | 
						
							| 8 | 3 | imbi2d | ⊢ ( 〈 𝑧 ,  𝑤 〉  =  𝐵  →  ( ( ( 𝑣  ∈  𝐷  ∧  𝑢  ∈  𝐹 )  →  𝜓 )  ↔  ( ( 𝑣  ∈  𝐷  ∧  𝑢  ∈  𝐹 )  →  𝜒 ) ) ) | 
						
							| 9 | 5 | 3expia | ⊢ ( ( ( 𝑥  ∈  𝐷  ∧  𝑦  ∈  𝐹 )  ∧  ( 𝑧  ∈  𝐷  ∧  𝑤  ∈  𝐹 ) )  →  ( ( 𝑣  ∈  𝐷  ∧  𝑢  ∈  𝐹 )  →  𝜑 ) ) | 
						
							| 10 | 1 7 8 9 | 2optocl | ⊢ ( ( 𝐴  ∈  𝑅  ∧  𝐵  ∈  𝑅 )  →  ( ( 𝑣  ∈  𝐷  ∧  𝑢  ∈  𝐹 )  →  𝜒 ) ) | 
						
							| 11 | 10 | com12 | ⊢ ( ( 𝑣  ∈  𝐷  ∧  𝑢  ∈  𝐹 )  →  ( ( 𝐴  ∈  𝑅  ∧  𝐵  ∈  𝑅 )  →  𝜒 ) ) | 
						
							| 12 | 1 6 11 | optocl | ⊢ ( 𝐶  ∈  𝑅  →  ( ( 𝐴  ∈  𝑅  ∧  𝐵  ∈  𝑅 )  →  𝜃 ) ) | 
						
							| 13 | 12 | impcom | ⊢ ( ( ( 𝐴  ∈  𝑅  ∧  𝐵  ∈  𝑅 )  ∧  𝐶  ∈  𝑅 )  →  𝜃 ) | 
						
							| 14 | 13 | 3impa | ⊢ ( ( 𝐴  ∈  𝑅  ∧  𝐵  ∈  𝑅  ∧  𝐶  ∈  𝑅 )  →  𝜃 ) |