| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ltbval.c |  | 
						
							| 2 |  | ltbval.d |  | 
						
							| 3 |  | ltbval.i |  | 
						
							| 4 |  | ltbval.t |  | 
						
							| 5 |  | elex |  | 
						
							| 6 |  | elex |  | 
						
							| 7 |  | simpr |  | 
						
							| 8 | 7 | oveq2d |  | 
						
							| 9 |  | rabeq |  | 
						
							| 10 | 8 9 | syl |  | 
						
							| 11 | 10 2 | eqtr4di |  | 
						
							| 12 | 11 | sseq2d |  | 
						
							| 13 |  | simpl |  | 
						
							| 14 | 13 | breqd |  | 
						
							| 15 | 14 | imbi1d |  | 
						
							| 16 | 7 15 | raleqbidv |  | 
						
							| 17 | 16 | anbi2d |  | 
						
							| 18 | 7 17 | rexeqbidv |  | 
						
							| 19 | 12 18 | anbi12d |  | 
						
							| 20 | 19 | opabbidv |  | 
						
							| 21 |  | df-ltbag |  | 
						
							| 22 |  | vex |  | 
						
							| 23 |  | vex |  | 
						
							| 24 | 22 23 | prss |  | 
						
							| 25 | 24 | anbi1i |  | 
						
							| 26 | 25 | opabbii |  | 
						
							| 27 |  | ovex |  | 
						
							| 28 | 2 27 | rabex2 |  | 
						
							| 29 | 28 28 | xpex |  | 
						
							| 30 |  | opabssxp |  | 
						
							| 31 | 29 30 | ssexi |  | 
						
							| 32 | 26 31 | eqeltrri |  | 
						
							| 33 | 20 21 32 | ovmpoa |  | 
						
							| 34 | 5 6 33 | syl2an |  | 
						
							| 35 | 4 3 34 | syl2anc |  | 
						
							| 36 | 1 35 | eqtrid |  |