| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							nmmul.x | 
							   | 
						
						
							| 2 | 
							
								
							 | 
							nmmul.n | 
							   | 
						
						
							| 3 | 
							
								
							 | 
							nmmul.t | 
							   | 
						
						
							| 4 | 
							
								
							 | 
							nrgdsdi.d | 
							   | 
						
						
							| 5 | 
							
								
							 | 
							simpl | 
							   | 
						
						
							| 6 | 
							
								
							 | 
							nrgring | 
							   | 
						
						
							| 7 | 
							
								6
							 | 
							adantr | 
							   | 
						
						
							| 8 | 
							
								
							 | 
							ringgrp | 
							   | 
						
						
							| 9 | 
							
								7 8
							 | 
							syl | 
							   | 
						
						
							| 10 | 
							
								
							 | 
							simpr1 | 
							   | 
						
						
							| 11 | 
							
								
							 | 
							simpr2 | 
							   | 
						
						
							| 12 | 
							
								
							 | 
							eqid | 
							   | 
						
						
							| 13 | 
							
								1 12
							 | 
							grpsubcl | 
							   | 
						
						
							| 14 | 
							
								9 10 11 13
							 | 
							syl3anc | 
							   | 
						
						
							| 15 | 
							
								
							 | 
							simpr3 | 
							   | 
						
						
							| 16 | 
							
								1 2 3
							 | 
							nmmul | 
							   | 
						
						
							| 17 | 
							
								5 14 15 16
							 | 
							syl3anc | 
							   | 
						
						
							| 18 | 
							
								1 3 12 7 10 11 15
							 | 
							ringsubdir | 
							   | 
						
						
							| 19 | 
							
								18
							 | 
							fveq2d | 
							   | 
						
						
							| 20 | 
							
								17 19
							 | 
							eqtr3d | 
							   | 
						
						
							| 21 | 
							
								
							 | 
							nrgngp | 
							   | 
						
						
							| 22 | 
							
								21
							 | 
							adantr | 
							   | 
						
						
							| 23 | 
							
								2 1 12 4
							 | 
							ngpds | 
							   | 
						
						
							| 24 | 
							
								22 10 11 23
							 | 
							syl3anc | 
							   | 
						
						
							| 25 | 
							
								24
							 | 
							oveq1d | 
							   | 
						
						
							| 26 | 
							
								1 3
							 | 
							ringcl | 
							   | 
						
						
							| 27 | 
							
								7 10 15 26
							 | 
							syl3anc | 
							   | 
						
						
							| 28 | 
							
								1 3
							 | 
							ringcl | 
							   | 
						
						
							| 29 | 
							
								7 11 15 28
							 | 
							syl3anc | 
							   | 
						
						
							| 30 | 
							
								2 1 12 4
							 | 
							ngpds | 
							   | 
						
						
							| 31 | 
							
								22 27 29 30
							 | 
							syl3anc | 
							   | 
						
						
							| 32 | 
							
								20 25 31
							 | 
							3eqtr4d | 
							   |