| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mercolem3 | ⊢ ( ( 𝜓  →  𝜒 )  →  ( 𝜓  →  ( 𝜑  →  𝜒 ) ) ) | 
						
							| 2 |  | mercolem8 | ⊢ ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) | 
						
							| 3 |  | mercolem6 | ⊢ ( ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) )  →  ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) | 
						
							| 4 | 2 3 | ax-mp | ⊢ ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) | 
						
							| 5 |  | mercolem3 | ⊢ ( ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) )  →  ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) ) | 
						
							| 6 | 4 5 | ax-mp | ⊢ ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) | 
						
							| 7 |  | mercolem8 | ⊢ ( ( ( 𝜓  →  𝜒 )  →  ( 𝜓  →  ( 𝜑  →  𝜒 ) ) )  →  ( ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) )  →  ( ( ( 𝜓  →  𝜒 )  →  ( 𝜓  →  ( 𝜑  →  𝜒 ) ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) ) ) ) | 
						
							| 8 |  | mercolem6 | ⊢ ( ( ( ( 𝜓  →  𝜒 )  →  ( 𝜓  →  ( 𝜑  →  𝜒 ) ) )  →  ( ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) )  →  ( ( ( 𝜓  →  𝜒 )  →  ( 𝜓  →  ( 𝜑  →  𝜒 ) ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) ) ) )  →  ( ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) )  →  ( ( ( 𝜓  →  𝜒 )  →  ( 𝜓  →  ( 𝜑  →  𝜒 ) ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) ) ) ) | 
						
							| 9 | 7 8 | ax-mp | ⊢ ( ( ( 𝜓  →  ( 𝜑  →  𝜒 ) )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) )  →  ( ( ( 𝜓  →  𝜒 )  →  ( 𝜓  →  ( 𝜑  →  𝜒 ) ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) ) ) | 
						
							| 10 | 6 9 | ax-mp | ⊢ ( ( ( 𝜓  →  𝜒 )  →  ( 𝜓  →  ( 𝜑  →  𝜒 ) ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) ) | 
						
							| 11 | 1 10 | ax-mp | ⊢ ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) | 
						
							| 12 |  | mercolem6 | ⊢ ( ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) )  →  ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) ) | 
						
							| 13 | 11 12 | ax-mp | ⊢ ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) | 
						
							| 14 |  | mercolem6 | ⊢ ( ( ( 𝜓  →  𝜒 )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) )  →  ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) ) | 
						
							| 15 | 13 14 | ax-mp | ⊢ ( ( 𝜑  →  𝜓 )  →  ( ( 𝜓  →  𝜒 )  →  ( 𝜑  →  𝜒 ) ) ) |