| Step | Hyp | Ref | Expression | 
						
							| 1 |  | diam.m |  | 
						
							| 2 |  | diam.h |  | 
						
							| 3 |  | diam.i |  | 
						
							| 4 |  | simpl |  | 
						
							| 5 | 2 3 | diacnvclN |  | 
						
							| 6 | 5 | adantrr |  | 
						
							| 7 | 2 3 | diacnvclN |  | 
						
							| 8 | 7 | adantrl |  | 
						
							| 9 | 1 2 3 | diameetN |  | 
						
							| 10 | 4 6 8 9 | syl12anc |  | 
						
							| 11 | 2 3 | diaf11N |  | 
						
							| 12 | 11 | adantr |  | 
						
							| 13 |  | simprl |  | 
						
							| 14 |  | f1ocnvfv2 |  | 
						
							| 15 | 12 13 14 | syl2anc |  | 
						
							| 16 |  | simprr |  | 
						
							| 17 |  | f1ocnvfv2 |  | 
						
							| 18 | 12 16 17 | syl2anc |  | 
						
							| 19 | 15 18 | ineq12d |  | 
						
							| 20 | 10 19 | eqtr2d |  |