| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-refld |  | 
						
							| 2 | 1 | oveq1i |  | 
						
							| 3 |  | resubdrg |  | 
						
							| 4 | 3 | simpli |  | 
						
							| 5 |  | nn0ssre |  | 
						
							| 6 |  | ressabs |  | 
						
							| 7 | 4 5 6 | mp2an |  | 
						
							| 8 | 2 7 | eqtri |  | 
						
							| 9 |  | retos |  | 
						
							| 10 |  | rearchi |  | 
						
							| 11 | 9 10 | pm3.2i |  | 
						
							| 12 |  | nn0subm |  | 
						
							| 13 |  | subrgsubg |  | 
						
							| 14 |  | subgsubm |  | 
						
							| 15 | 4 13 14 | mp2b |  | 
						
							| 16 | 1 | subsubm |  | 
						
							| 17 | 15 16 | ax-mp |  | 
						
							| 18 | 12 5 17 | mpbir2an |  | 
						
							| 19 |  | submarchi |  | 
						
							| 20 | 11 18 19 | mp2an |  | 
						
							| 21 | 8 20 | eqeltrri |  |