| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simpl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> D e. ( PsMet ` X ) ) | 
						
							| 2 |  | metidss |  |-  ( D e. ( PsMet ` X ) -> ( ~Met ` D ) C_ ( X X. X ) ) | 
						
							| 3 |  | dmss |  |-  ( ( ~Met ` D ) C_ ( X X. X ) -> dom ( ~Met ` D ) C_ dom ( X X. X ) ) | 
						
							| 4 | 2 3 | syl |  |-  ( D e. ( PsMet ` X ) -> dom ( ~Met ` D ) C_ dom ( X X. X ) ) | 
						
							| 5 |  | dmxpid |  |-  dom ( X X. X ) = X | 
						
							| 6 | 4 5 | sseqtrdi |  |-  ( D e. ( PsMet ` X ) -> dom ( ~Met ` D ) C_ X ) | 
						
							| 7 | 1 6 | syl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> dom ( ~Met ` D ) C_ X ) | 
						
							| 8 |  | xpss |  |-  ( X X. X ) C_ ( _V X. _V ) | 
						
							| 9 | 2 8 | sstrdi |  |-  ( D e. ( PsMet ` X ) -> ( ~Met ` D ) C_ ( _V X. _V ) ) | 
						
							| 10 |  | df-rel |  |-  ( Rel ( ~Met ` D ) <-> ( ~Met ` D ) C_ ( _V X. _V ) ) | 
						
							| 11 | 9 10 | sylibr |  |-  ( D e. ( PsMet ` X ) -> Rel ( ~Met ` D ) ) | 
						
							| 12 | 1 11 | syl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> Rel ( ~Met ` D ) ) | 
						
							| 13 |  | simprl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> A ( ~Met ` D ) B ) | 
						
							| 14 |  | releldm |  |-  ( ( Rel ( ~Met ` D ) /\ A ( ~Met ` D ) B ) -> A e. dom ( ~Met ` D ) ) | 
						
							| 15 | 12 13 14 | syl2anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> A e. dom ( ~Met ` D ) ) | 
						
							| 16 | 7 15 | sseldd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> A e. X ) | 
						
							| 17 |  | simprr |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> E ( ~Met ` D ) F ) | 
						
							| 18 |  | releldm |  |-  ( ( Rel ( ~Met ` D ) /\ E ( ~Met ` D ) F ) -> E e. dom ( ~Met ` D ) ) | 
						
							| 19 | 12 17 18 | syl2anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> E e. dom ( ~Met ` D ) ) | 
						
							| 20 | 7 19 | sseldd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> E e. X ) | 
						
							| 21 |  | psmetsym |  |-  ( ( D e. ( PsMet ` X ) /\ A e. X /\ E e. X ) -> ( A D E ) = ( E D A ) ) | 
						
							| 22 | 1 16 20 21 | syl3anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D E ) = ( E D A ) ) | 
						
							| 23 |  | psmetf |  |-  ( D e. ( PsMet ` X ) -> D : ( X X. X ) --> RR* ) | 
						
							| 24 | 23 | fovcdmda |  |-  ( ( D e. ( PsMet ` X ) /\ ( E e. X /\ A e. X ) ) -> ( E D A ) e. RR* ) | 
						
							| 25 | 1 20 16 24 | syl12anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( E D A ) e. RR* ) | 
						
							| 26 | 22 25 | eqeltrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D E ) e. RR* ) | 
						
							| 27 |  | rnss |  |-  ( ( ~Met ` D ) C_ ( X X. X ) -> ran ( ~Met ` D ) C_ ran ( X X. X ) ) | 
						
							| 28 | 2 27 | syl |  |-  ( D e. ( PsMet ` X ) -> ran ( ~Met ` D ) C_ ran ( X X. X ) ) | 
						
							| 29 |  | rnxpid |  |-  ran ( X X. X ) = X | 
						
							| 30 | 28 29 | sseqtrdi |  |-  ( D e. ( PsMet ` X ) -> ran ( ~Met ` D ) C_ X ) | 
						
							| 31 | 1 30 | syl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ran ( ~Met ` D ) C_ X ) | 
						
							| 32 |  | relelrn |  |-  ( ( Rel ( ~Met ` D ) /\ A ( ~Met ` D ) B ) -> B e. ran ( ~Met ` D ) ) | 
						
							| 33 | 12 13 32 | syl2anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> B e. ran ( ~Met ` D ) ) | 
						
							| 34 | 31 33 | sseldd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> B e. X ) | 
						
							| 35 | 23 | fovcdmda |  |-  ( ( D e. ( PsMet ` X ) /\ ( B e. X /\ E e. X ) ) -> ( B D E ) e. RR* ) | 
						
							| 36 | 1 34 20 35 | syl12anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( B D E ) e. RR* ) | 
						
							| 37 |  | relelrn |  |-  ( ( Rel ( ~Met ` D ) /\ E ( ~Met ` D ) F ) -> F e. ran ( ~Met ` D ) ) | 
						
							| 38 | 12 17 37 | syl2anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> F e. ran ( ~Met ` D ) ) | 
						
							| 39 | 31 38 | sseldd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> F e. X ) | 
						
							| 40 |  | psmetsym |  |-  ( ( D e. ( PsMet ` X ) /\ F e. X /\ B e. X ) -> ( F D B ) = ( B D F ) ) | 
						
							| 41 | 1 39 34 40 | syl3anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( F D B ) = ( B D F ) ) | 
						
							| 42 | 23 | fovcdmda |  |-  ( ( D e. ( PsMet ` X ) /\ ( F e. X /\ B e. X ) ) -> ( F D B ) e. RR* ) | 
						
							| 43 | 1 39 34 42 | syl12anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( F D B ) e. RR* ) | 
						
							| 44 | 41 43 | eqeltrrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( B D F ) e. RR* ) | 
						
							| 45 |  | psmettri2 |  |-  ( ( D e. ( PsMet ` X ) /\ ( B e. X /\ A e. X /\ E e. X ) ) -> ( A D E ) <_ ( ( B D A ) +e ( B D E ) ) ) | 
						
							| 46 | 1 34 16 20 45 | syl13anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D E ) <_ ( ( B D A ) +e ( B D E ) ) ) | 
						
							| 47 |  | psmetsym |  |-  ( ( D e. ( PsMet ` X ) /\ A e. X /\ B e. X ) -> ( A D B ) = ( B D A ) ) | 
						
							| 48 | 1 16 34 47 | syl3anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D B ) = ( B D A ) ) | 
						
							| 49 | 16 34 | jca |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A e. X /\ B e. X ) ) | 
						
							| 50 |  | metidv |  |-  ( ( D e. ( PsMet ` X ) /\ ( A e. X /\ B e. X ) ) -> ( A ( ~Met ` D ) B <-> ( A D B ) = 0 ) ) | 
						
							| 51 | 50 | biimpa |  |-  ( ( ( D e. ( PsMet ` X ) /\ ( A e. X /\ B e. X ) ) /\ A ( ~Met ` D ) B ) -> ( A D B ) = 0 ) | 
						
							| 52 | 1 49 13 51 | syl21anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D B ) = 0 ) | 
						
							| 53 | 48 52 | eqtr3d |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( B D A ) = 0 ) | 
						
							| 54 | 53 | oveq1d |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( B D A ) +e ( B D E ) ) = ( 0 +e ( B D E ) ) ) | 
						
							| 55 |  | xaddlid |  |-  ( ( B D E ) e. RR* -> ( 0 +e ( B D E ) ) = ( B D E ) ) | 
						
							| 56 | 36 55 | syl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( 0 +e ( B D E ) ) = ( B D E ) ) | 
						
							| 57 | 54 56 | eqtrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( B D A ) +e ( B D E ) ) = ( B D E ) ) | 
						
							| 58 | 46 57 | breqtrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D E ) <_ ( B D E ) ) | 
						
							| 59 |  | psmettri2 |  |-  ( ( D e. ( PsMet ` X ) /\ ( F e. X /\ B e. X /\ E e. X ) ) -> ( B D E ) <_ ( ( F D B ) +e ( F D E ) ) ) | 
						
							| 60 | 1 39 34 20 59 | syl13anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( B D E ) <_ ( ( F D B ) +e ( F D E ) ) ) | 
						
							| 61 |  | psmetsym |  |-  ( ( D e. ( PsMet ` X ) /\ F e. X /\ E e. X ) -> ( F D E ) = ( E D F ) ) | 
						
							| 62 | 1 39 20 61 | syl3anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( F D E ) = ( E D F ) ) | 
						
							| 63 | 20 39 | jca |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( E e. X /\ F e. X ) ) | 
						
							| 64 |  | metidv |  |-  ( ( D e. ( PsMet ` X ) /\ ( E e. X /\ F e. X ) ) -> ( E ( ~Met ` D ) F <-> ( E D F ) = 0 ) ) | 
						
							| 65 | 64 | biimpa |  |-  ( ( ( D e. ( PsMet ` X ) /\ ( E e. X /\ F e. X ) ) /\ E ( ~Met ` D ) F ) -> ( E D F ) = 0 ) | 
						
							| 66 | 1 63 17 65 | syl21anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( E D F ) = 0 ) | 
						
							| 67 | 62 66 | eqtrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( F D E ) = 0 ) | 
						
							| 68 | 67 | oveq2d |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( F D B ) +e ( F D E ) ) = ( ( F D B ) +e 0 ) ) | 
						
							| 69 |  | xaddrid |  |-  ( ( F D B ) e. RR* -> ( ( F D B ) +e 0 ) = ( F D B ) ) | 
						
							| 70 | 43 69 | syl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( F D B ) +e 0 ) = ( F D B ) ) | 
						
							| 71 | 68 70 41 | 3eqtrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( F D B ) +e ( F D E ) ) = ( B D F ) ) | 
						
							| 72 | 60 71 | breqtrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( B D E ) <_ ( B D F ) ) | 
						
							| 73 | 26 36 44 58 72 | xrletrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D E ) <_ ( B D F ) ) | 
						
							| 74 | 23 | fovcdmda |  |-  ( ( D e. ( PsMet ` X ) /\ ( A e. X /\ F e. X ) ) -> ( A D F ) e. RR* ) | 
						
							| 75 | 1 16 39 74 | syl12anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D F ) e. RR* ) | 
						
							| 76 |  | psmettri2 |  |-  ( ( D e. ( PsMet ` X ) /\ ( A e. X /\ B e. X /\ F e. X ) ) -> ( B D F ) <_ ( ( A D B ) +e ( A D F ) ) ) | 
						
							| 77 | 1 16 34 39 76 | syl13anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( B D F ) <_ ( ( A D B ) +e ( A D F ) ) ) | 
						
							| 78 | 52 | oveq1d |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( A D B ) +e ( A D F ) ) = ( 0 +e ( A D F ) ) ) | 
						
							| 79 |  | xaddlid |  |-  ( ( A D F ) e. RR* -> ( 0 +e ( A D F ) ) = ( A D F ) ) | 
						
							| 80 | 75 79 | syl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( 0 +e ( A D F ) ) = ( A D F ) ) | 
						
							| 81 | 78 80 | eqtrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( A D B ) +e ( A D F ) ) = ( A D F ) ) | 
						
							| 82 | 77 81 | breqtrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( B D F ) <_ ( A D F ) ) | 
						
							| 83 |  | psmettri2 |  |-  ( ( D e. ( PsMet ` X ) /\ ( E e. X /\ A e. X /\ F e. X ) ) -> ( A D F ) <_ ( ( E D A ) +e ( E D F ) ) ) | 
						
							| 84 | 1 20 16 39 83 | syl13anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D F ) <_ ( ( E D A ) +e ( E D F ) ) ) | 
						
							| 85 |  | xaddrid |  |-  ( ( E D A ) e. RR* -> ( ( E D A ) +e 0 ) = ( E D A ) ) | 
						
							| 86 | 25 85 | syl |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( E D A ) +e 0 ) = ( E D A ) ) | 
						
							| 87 | 66 | oveq2d |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( E D A ) +e ( E D F ) ) = ( ( E D A ) +e 0 ) ) | 
						
							| 88 | 86 87 22 | 3eqtr4d |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( E D A ) +e ( E D F ) ) = ( A D E ) ) | 
						
							| 89 | 84 88 | breqtrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D F ) <_ ( A D E ) ) | 
						
							| 90 | 44 75 26 82 89 | xrletrd |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( B D F ) <_ ( A D E ) ) | 
						
							| 91 |  | xrletri3 |  |-  ( ( ( A D E ) e. RR* /\ ( B D F ) e. RR* ) -> ( ( A D E ) = ( B D F ) <-> ( ( A D E ) <_ ( B D F ) /\ ( B D F ) <_ ( A D E ) ) ) ) | 
						
							| 92 | 26 44 91 | syl2anc |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( ( A D E ) = ( B D F ) <-> ( ( A D E ) <_ ( B D F ) /\ ( B D F ) <_ ( A D E ) ) ) ) | 
						
							| 93 | 73 90 92 | mpbir2and |  |-  ( ( D e. ( PsMet ` X ) /\ ( A ( ~Met ` D ) B /\ E ( ~Met ` D ) F ) ) -> ( A D E ) = ( B D F ) ) |