| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 0sno |  |-  0s e. No | 
						
							| 2 |  | 1nns |  |-  1s e. NN_s | 
						
							| 3 |  | 0slt1s |  |-  0s  | 
						
							| 4 |  | 1sno |  |-  1s e. No | 
						
							| 5 |  | sltneg |  |-  ( ( 0s e. No /\ 1s e. No ) -> ( 0s  ( -us ` 1s )  | 
						
							| 6 | 1 4 5 | mp2an |  |-  ( 0s  ( -us ` 1s )  | 
						
							| 7 | 3 6 | mpbi |  |-  ( -us ` 1s )  | 
						
							| 8 |  | negs0s |  |-  ( -us ` 0s ) = 0s | 
						
							| 9 | 7 8 | breqtri |  |-  ( -us ` 1s )  | 
						
							| 10 | 9 3 | pm3.2i |  |-  ( ( -us ` 1s )  | 
						
							| 11 |  | fveq2 |  |-  ( n = 1s -> ( -us ` n ) = ( -us ` 1s ) ) | 
						
							| 12 | 11 | breq1d |  |-  ( n = 1s -> ( ( -us ` n )  ( -us ` 1s )  | 
						
							| 13 |  | breq2 |  |-  ( n = 1s -> ( 0s  0s  | 
						
							| 14 | 12 13 | anbi12d |  |-  ( n = 1s -> ( ( ( -us ` n )  ( ( -us ` 1s )  | 
						
							| 15 | 14 | rspcev |  |-  ( ( 1s e. NN_s /\ ( ( -us ` 1s )  E. n e. NN_s ( ( -us ` n )  | 
						
							| 16 | 2 10 15 | mp2an |  |-  E. n e. NN_s ( ( -us ` n )  | 
						
							| 17 | 4 | a1i |  |-  ( n e. NN_s -> 1s e. No ) | 
						
							| 18 |  | nnsno |  |-  ( n e. NN_s -> n e. No ) | 
						
							| 19 |  | nnne0s |  |-  ( n e. NN_s -> n =/= 0s ) | 
						
							| 20 | 17 18 19 | divscld |  |-  ( n e. NN_s -> ( 1s /su n ) e. No ) | 
						
							| 21 | 20 | negsval2d |  |-  ( n e. NN_s -> ( -us ` ( 1s /su n ) ) = ( 0s -s ( 1s /su n ) ) ) | 
						
							| 22 | 21 | eqeq2d |  |-  ( n e. NN_s -> ( x = ( -us ` ( 1s /su n ) ) <-> x = ( 0s -s ( 1s /su n ) ) ) ) | 
						
							| 23 | 22 | bicomd |  |-  ( n e. NN_s -> ( x = ( 0s -s ( 1s /su n ) ) <-> x = ( -us ` ( 1s /su n ) ) ) ) | 
						
							| 24 | 23 | rexbiia |  |-  ( E. n e. NN_s x = ( 0s -s ( 1s /su n ) ) <-> E. n e. NN_s x = ( -us ` ( 1s /su n ) ) ) | 
						
							| 25 | 24 | abbii |  |-  { x | E. n e. NN_s x = ( 0s -s ( 1s /su n ) ) } = { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } | 
						
							| 26 |  | addslid |  |-  ( ( 1s /su n ) e. No -> ( 0s +s ( 1s /su n ) ) = ( 1s /su n ) ) | 
						
							| 27 | 20 26 | syl |  |-  ( n e. NN_s -> ( 0s +s ( 1s /su n ) ) = ( 1s /su n ) ) | 
						
							| 28 | 27 | eqeq2d |  |-  ( n e. NN_s -> ( x = ( 0s +s ( 1s /su n ) ) <-> x = ( 1s /su n ) ) ) | 
						
							| 29 | 28 | rexbiia |  |-  ( E. n e. NN_s x = ( 0s +s ( 1s /su n ) ) <-> E. n e. NN_s x = ( 1s /su n ) ) | 
						
							| 30 | 29 | abbii |  |-  { x | E. n e. NN_s x = ( 0s +s ( 1s /su n ) ) } = { x | E. n e. NN_s x = ( 1s /su n ) } | 
						
							| 31 | 25 30 | oveq12i |  |-  ( { x | E. n e. NN_s x = ( 0s -s ( 1s /su n ) ) } |s { x | E. n e. NN_s x = ( 0s +s ( 1s /su n ) ) } ) = ( { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } |s { x | E. n e. NN_s x = ( 1s /su n ) } ) | 
						
							| 32 |  | nnsex |  |-  NN_s e. _V | 
						
							| 33 | 32 | abrexex |  |-  { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } e. _V | 
						
							| 34 | 33 | a1i |  |-  ( T. -> { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } e. _V ) | 
						
							| 35 |  | snex |  |-  { 0s } e. _V | 
						
							| 36 | 35 | a1i |  |-  ( T. -> { 0s } e. _V ) | 
						
							| 37 | 20 | negscld |  |-  ( n e. NN_s -> ( -us ` ( 1s /su n ) ) e. No ) | 
						
							| 38 |  | eleq1 |  |-  ( x = ( -us ` ( 1s /su n ) ) -> ( x e. No <-> ( -us ` ( 1s /su n ) ) e. No ) ) | 
						
							| 39 | 37 38 | syl5ibrcom |  |-  ( n e. NN_s -> ( x = ( -us ` ( 1s /su n ) ) -> x e. No ) ) | 
						
							| 40 | 39 | rexlimiv |  |-  ( E. n e. NN_s x = ( -us ` ( 1s /su n ) ) -> x e. No ) | 
						
							| 41 | 40 | a1i |  |-  ( T. -> ( E. n e. NN_s x = ( -us ` ( 1s /su n ) ) -> x e. No ) ) | 
						
							| 42 | 41 | abssdv |  |-  ( T. -> { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } C_ No ) | 
						
							| 43 | 1 | a1i |  |-  ( T. -> 0s e. No ) | 
						
							| 44 | 43 | snssd |  |-  ( T. -> { 0s } C_ No ) | 
						
							| 45 |  | vex |  |-  z e. _V | 
						
							| 46 |  | eqeq1 |  |-  ( x = z -> ( x = ( -us ` ( 1s /su n ) ) <-> z = ( -us ` ( 1s /su n ) ) ) ) | 
						
							| 47 | 46 | rexbidv |  |-  ( x = z -> ( E. n e. NN_s x = ( -us ` ( 1s /su n ) ) <-> E. n e. NN_s z = ( -us ` ( 1s /su n ) ) ) ) | 
						
							| 48 | 45 47 | elab |  |-  ( z e. { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } <-> E. n e. NN_s z = ( -us ` ( 1s /su n ) ) ) | 
						
							| 49 |  | velsn |  |-  ( y e. { 0s } <-> y = 0s ) | 
						
							| 50 | 48 49 | anbi12i |  |-  ( ( z e. { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } /\ y e. { 0s } ) <-> ( E. n e. NN_s z = ( -us ` ( 1s /su n ) ) /\ y = 0s ) ) | 
						
							| 51 |  | r19.41v |  |-  ( E. n e. NN_s ( z = ( -us ` ( 1s /su n ) ) /\ y = 0s ) <-> ( E. n e. NN_s z = ( -us ` ( 1s /su n ) ) /\ y = 0s ) ) | 
						
							| 52 | 50 51 | bitr4i |  |-  ( ( z e. { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } /\ y e. { 0s } ) <-> E. n e. NN_s ( z = ( -us ` ( 1s /su n ) ) /\ y = 0s ) ) | 
						
							| 53 |  | muls02 |  |-  ( n e. No -> ( 0s x.s n ) = 0s ) | 
						
							| 54 | 18 53 | syl |  |-  ( n e. NN_s -> ( 0s x.s n ) = 0s ) | 
						
							| 55 | 54 3 | eqbrtrdi |  |-  ( n e. NN_s -> ( 0s x.s n )  | 
						
							| 56 | 1 | a1i |  |-  ( n e. NN_s -> 0s e. No ) | 
						
							| 57 |  | nnsgt0 |  |-  ( n e. NN_s -> 0s  | 
						
							| 58 | 56 17 18 57 | sltmuldivd |  |-  ( n e. NN_s -> ( ( 0s x.s n )  0s  | 
						
							| 59 | 55 58 | mpbid |  |-  ( n e. NN_s -> 0s  | 
						
							| 60 | 20 | slt0neg2d |  |-  ( n e. NN_s -> ( 0s  ( -us ` ( 1s /su n ) )  | 
						
							| 61 | 59 60 | mpbid |  |-  ( n e. NN_s -> ( -us ` ( 1s /su n ) )  | 
						
							| 62 |  | breq12 |  |-  ( ( z = ( -us ` ( 1s /su n ) ) /\ y = 0s ) -> ( z  ( -us ` ( 1s /su n ) )  | 
						
							| 63 | 61 62 | syl5ibrcom |  |-  ( n e. NN_s -> ( ( z = ( -us ` ( 1s /su n ) ) /\ y = 0s ) -> z  | 
						
							| 64 | 63 | rexlimiv |  |-  ( E. n e. NN_s ( z = ( -us ` ( 1s /su n ) ) /\ y = 0s ) -> z  | 
						
							| 65 | 52 64 | sylbi |  |-  ( ( z e. { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } /\ y e. { 0s } ) -> z  | 
						
							| 66 | 65 | 3adant1 |  |-  ( ( T. /\ z e. { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } /\ y e. { 0s } ) -> z  | 
						
							| 67 | 34 36 42 44 66 | ssltd |  |-  ( T. -> { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } < | 
						
							| 68 | 32 | abrexex |  |-  { x | E. n e. NN_s x = ( 1s /su n ) } e. _V | 
						
							| 69 | 68 | a1i |  |-  ( T. -> { x | E. n e. NN_s x = ( 1s /su n ) } e. _V ) | 
						
							| 70 |  | eleq1 |  |-  ( x = ( 1s /su n ) -> ( x e. No <-> ( 1s /su n ) e. No ) ) | 
						
							| 71 | 20 70 | syl5ibrcom |  |-  ( n e. NN_s -> ( x = ( 1s /su n ) -> x e. No ) ) | 
						
							| 72 | 71 | rexlimiv |  |-  ( E. n e. NN_s x = ( 1s /su n ) -> x e. No ) | 
						
							| 73 | 72 | a1i |  |-  ( T. -> ( E. n e. NN_s x = ( 1s /su n ) -> x e. No ) ) | 
						
							| 74 | 73 | abssdv |  |-  ( T. -> { x | E. n e. NN_s x = ( 1s /su n ) } C_ No ) | 
						
							| 75 |  | eqeq1 |  |-  ( x = z -> ( x = ( 1s /su n ) <-> z = ( 1s /su n ) ) ) | 
						
							| 76 | 75 | rexbidv |  |-  ( x = z -> ( E. n e. NN_s x = ( 1s /su n ) <-> E. n e. NN_s z = ( 1s /su n ) ) ) | 
						
							| 77 | 45 76 | elab |  |-  ( z e. { x | E. n e. NN_s x = ( 1s /su n ) } <-> E. n e. NN_s z = ( 1s /su n ) ) | 
						
							| 78 | 49 77 | anbi12i |  |-  ( ( y e. { 0s } /\ z e. { x | E. n e. NN_s x = ( 1s /su n ) } ) <-> ( y = 0s /\ E. n e. NN_s z = ( 1s /su n ) ) ) | 
						
							| 79 |  | r19.42v |  |-  ( E. n e. NN_s ( y = 0s /\ z = ( 1s /su n ) ) <-> ( y = 0s /\ E. n e. NN_s z = ( 1s /su n ) ) ) | 
						
							| 80 | 78 79 | bitr4i |  |-  ( ( y e. { 0s } /\ z e. { x | E. n e. NN_s x = ( 1s /su n ) } ) <-> E. n e. NN_s ( y = 0s /\ z = ( 1s /su n ) ) ) | 
						
							| 81 |  | breq12 |  |-  ( ( y = 0s /\ z = ( 1s /su n ) ) -> ( y  0s  | 
						
							| 82 | 59 81 | syl5ibrcom |  |-  ( n e. NN_s -> ( ( y = 0s /\ z = ( 1s /su n ) ) -> y  | 
						
							| 83 | 82 | rexlimiv |  |-  ( E. n e. NN_s ( y = 0s /\ z = ( 1s /su n ) ) -> y  | 
						
							| 84 | 83 | a1i |  |-  ( T. -> ( E. n e. NN_s ( y = 0s /\ z = ( 1s /su n ) ) -> y  | 
						
							| 85 | 80 84 | biimtrid |  |-  ( T. -> ( ( y e. { 0s } /\ z e. { x | E. n e. NN_s x = ( 1s /su n ) } ) -> y  | 
						
							| 86 | 85 | 3impib |  |-  ( ( T. /\ y e. { 0s } /\ z e. { x | E. n e. NN_s x = ( 1s /su n ) } ) -> y  | 
						
							| 87 | 36 69 44 74 86 | ssltd |  |-  ( T. -> { 0s } < | 
						
							| 88 | 67 87 | cuteq0 |  |-  ( T. -> ( { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } |s { x | E. n e. NN_s x = ( 1s /su n ) } ) = 0s ) | 
						
							| 89 | 88 | mptru |  |-  ( { x | E. n e. NN_s x = ( -us ` ( 1s /su n ) ) } |s { x | E. n e. NN_s x = ( 1s /su n ) } ) = 0s | 
						
							| 90 | 31 89 | eqtr2i |  |-  0s = ( { x | E. n e. NN_s x = ( 0s -s ( 1s /su n ) ) } |s { x | E. n e. NN_s x = ( 0s +s ( 1s /su n ) ) } ) | 
						
							| 91 | 16 90 | pm3.2i |  |-  ( E. n e. NN_s ( ( -us ` n )  | 
						
							| 92 |  | elreno |  |-  ( 0s e. RR_s <-> ( 0s e. No /\ ( E. n e. NN_s ( ( -us ` n )  | 
						
							| 93 | 1 91 92 | mpbir2an |  |-  0s e. RR_s |