| Step | Hyp | Ref | Expression | 
						
							| 1 |  | merco1 | ⊢ ( ( ( ( ( 𝜒  →  𝜑 )  →  ( 𝜏  →  ⊥ ) )  →  𝜑 )  →  ( 𝜑  →  𝜓 ) )  →  ( ( ( 𝜑  →  𝜓 )  →  𝜒 )  →  ( 𝜏  →  𝜒 ) ) ) | 
						
							| 2 |  | merco1lem2 | ⊢ ( ( ( ( ( ( 𝜒  →  𝜑 )  →  ( 𝜏  →  ⊥ ) )  →  𝜑 )  →  ( 𝜑  →  𝜓 ) )  →  ( ( ( 𝜑  →  𝜓 )  →  𝜒 )  →  ( 𝜏  →  𝜒 ) ) )  →  ( ( ( ( 𝜑  →  𝜓 )  →  ( 𝜃  →  ⊥ ) )  →  ( ( ( ( 𝜒  →  𝜑 )  →  ( 𝜏  →  ⊥ ) )  →  𝜑 )  →  ⊥ ) )  →  ( ( ( 𝜑  →  𝜓 )  →  𝜒 )  →  ( 𝜏  →  𝜒 ) ) ) ) | 
						
							| 3 | 1 2 | ax-mp | ⊢ ( ( ( ( 𝜑  →  𝜓 )  →  ( 𝜃  →  ⊥ ) )  →  ( ( ( ( 𝜒  →  𝜑 )  →  ( 𝜏  →  ⊥ ) )  →  𝜑 )  →  ⊥ ) )  →  ( ( ( 𝜑  →  𝜓 )  →  𝜒 )  →  ( 𝜏  →  𝜒 ) ) ) | 
						
							| 4 |  | merco1 | ⊢ ( ( ( ( ( 𝜑  →  𝜓 )  →  ( 𝜃  →  ⊥ ) )  →  ( ( ( ( 𝜒  →  𝜑 )  →  ( 𝜏  →  ⊥ ) )  →  𝜑 )  →  ⊥ ) )  →  ( ( ( 𝜑  →  𝜓 )  →  𝜒 )  →  ( 𝜏  →  𝜒 ) ) )  →  ( ( ( ( ( 𝜑  →  𝜓 )  →  𝜒 )  →  ( 𝜏  →  𝜒 ) )  →  𝜑 )  →  ( 𝜃  →  𝜑 ) ) ) | 
						
							| 5 | 3 4 | ax-mp | ⊢ ( ( ( ( ( 𝜑  →  𝜓 )  →  𝜒 )  →  ( 𝜏  →  𝜒 ) )  →  𝜑 )  →  ( 𝜃  →  𝜑 ) ) |