| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							cvrletr.b | 
							   | 
						
						
							| 2 | 
							
								
							 | 
							cvrletr.l | 
							   | 
						
						
							| 3 | 
							
								
							 | 
							cvrletr.s | 
							   | 
						
						
							| 4 | 
							
								
							 | 
							cvrletr.c | 
							   | 
						
						
							| 5 | 
							
								1 3 4
							 | 
							cvrnbtwn | 
							   | 
						
						
							| 6 | 
							
								2 3
							 | 
							pltval | 
							   | 
						
						
							| 7 | 
							
								6
							 | 
							3adant3r2 | 
							   | 
						
						
							| 8 | 
							
								7
							 | 
							3adant3 | 
							   | 
						
						
							| 9 | 
							
								8
							 | 
							anbi1d | 
							   | 
						
						
							| 10 | 
							
								9
							 | 
							notbid | 
							   | 
						
						
							| 11 | 
							
								
							 | 
							an32 | 
							   | 
						
						
							| 12 | 
							
								
							 | 
							df-ne | 
							   | 
						
						
							| 13 | 
							
								12
							 | 
							anbi2i | 
							   | 
						
						
							| 14 | 
							
								11 13
							 | 
							bitri | 
							   | 
						
						
							| 15 | 
							
								14
							 | 
							notbii | 
							   | 
						
						
							| 16 | 
							
								
							 | 
							iman | 
							   | 
						
						
							| 17 | 
							
								15 16
							 | 
							bitr4i | 
							   | 
						
						
							| 18 | 
							
								10 17
							 | 
							bitrdi | 
							   | 
						
						
							| 19 | 
							
								5 18
							 | 
							mpbid | 
							   | 
						
						
							| 20 | 
							
								1 2
							 | 
							posref | 
							   | 
						
						
							| 21 | 
							
								
							 | 
							breq2 | 
							   | 
						
						
							| 22 | 
							
								20 21
							 | 
							syl5ibcom | 
							   | 
						
						
							| 23 | 
							
								22
							 | 
							3ad2antr1 | 
							   | 
						
						
							| 24 | 
							
								23
							 | 
							3adant3 | 
							   | 
						
						
							| 25 | 
							
								
							 | 
							simp1 | 
							   | 
						
						
							| 26 | 
							
								
							 | 
							simp21 | 
							   | 
						
						
							| 27 | 
							
								
							 | 
							simp22 | 
							   | 
						
						
							| 28 | 
							
								
							 | 
							simp3 | 
							   | 
						
						
							| 29 | 
							
								1 3 4
							 | 
							cvrlt | 
							   | 
						
						
							| 30 | 
							
								25 26 27 28 29
							 | 
							syl31anc | 
							   | 
						
						
							| 31 | 
							
								
							 | 
							breq1 | 
							   | 
						
						
							| 32 | 
							
								30 31
							 | 
							syl5ibcom | 
							   | 
						
						
							| 33 | 
							
								24 32
							 | 
							jcad | 
							   | 
						
						
							| 34 | 
							
								19 33
							 | 
							impbid | 
							   |