| Step | Hyp | Ref | Expression | 
						
							| 1 |  | gonan0 |  |-  ( ( a |g b ) e. ( Fmla ` N ) -> N =/= (/) ) | 
						
							| 2 | 1 | adantl |  |-  ( ( N e. _om /\ ( a |g b ) e. ( Fmla ` N ) ) -> N =/= (/) ) | 
						
							| 3 |  | nnsuc |  |-  ( ( N e. _om /\ N =/= (/) ) -> E. x e. _om N = suc x ) | 
						
							| 4 |  | suceq |  |-  ( d = (/) -> suc d = suc (/) ) | 
						
							| 5 | 4 | fveq2d |  |-  ( d = (/) -> ( Fmla ` suc d ) = ( Fmla ` suc (/) ) ) | 
						
							| 6 | 5 | eleq2d |  |-  ( d = (/) -> ( ( a |g b ) e. ( Fmla ` suc d ) <-> ( a |g b ) e. ( Fmla ` suc (/) ) ) ) | 
						
							| 7 | 5 | eleq2d |  |-  ( d = (/) -> ( a e. ( Fmla ` suc d ) <-> a e. ( Fmla ` suc (/) ) ) ) | 
						
							| 8 | 5 | eleq2d |  |-  ( d = (/) -> ( b e. ( Fmla ` suc d ) <-> b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 9 | 7 8 | anbi12d |  |-  ( d = (/) -> ( ( a e. ( Fmla ` suc d ) /\ b e. ( Fmla ` suc d ) ) <-> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 10 | 6 9 | imbi12d |  |-  ( d = (/) -> ( ( ( a |g b ) e. ( Fmla ` suc d ) -> ( a e. ( Fmla ` suc d ) /\ b e. ( Fmla ` suc d ) ) ) <-> ( ( a |g b ) e. ( Fmla ` suc (/) ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) ) | 
						
							| 11 |  | suceq |  |-  ( d = c -> suc d = suc c ) | 
						
							| 12 | 11 | fveq2d |  |-  ( d = c -> ( Fmla ` suc d ) = ( Fmla ` suc c ) ) | 
						
							| 13 | 12 | eleq2d |  |-  ( d = c -> ( ( a |g b ) e. ( Fmla ` suc d ) <-> ( a |g b ) e. ( Fmla ` suc c ) ) ) | 
						
							| 14 | 12 | eleq2d |  |-  ( d = c -> ( a e. ( Fmla ` suc d ) <-> a e. ( Fmla ` suc c ) ) ) | 
						
							| 15 | 12 | eleq2d |  |-  ( d = c -> ( b e. ( Fmla ` suc d ) <-> b e. ( Fmla ` suc c ) ) ) | 
						
							| 16 | 14 15 | anbi12d |  |-  ( d = c -> ( ( a e. ( Fmla ` suc d ) /\ b e. ( Fmla ` suc d ) ) <-> ( a e. ( Fmla ` suc c ) /\ b e. ( Fmla ` suc c ) ) ) ) | 
						
							| 17 | 13 16 | imbi12d |  |-  ( d = c -> ( ( ( a |g b ) e. ( Fmla ` suc d ) -> ( a e. ( Fmla ` suc d ) /\ b e. ( Fmla ` suc d ) ) ) <-> ( ( a |g b ) e. ( Fmla ` suc c ) -> ( a e. ( Fmla ` suc c ) /\ b e. ( Fmla ` suc c ) ) ) ) ) | 
						
							| 18 |  | suceq |  |-  ( d = suc c -> suc d = suc suc c ) | 
						
							| 19 | 18 | fveq2d |  |-  ( d = suc c -> ( Fmla ` suc d ) = ( Fmla ` suc suc c ) ) | 
						
							| 20 | 19 | eleq2d |  |-  ( d = suc c -> ( ( a |g b ) e. ( Fmla ` suc d ) <-> ( a |g b ) e. ( Fmla ` suc suc c ) ) ) | 
						
							| 21 | 19 | eleq2d |  |-  ( d = suc c -> ( a e. ( Fmla ` suc d ) <-> a e. ( Fmla ` suc suc c ) ) ) | 
						
							| 22 | 19 | eleq2d |  |-  ( d = suc c -> ( b e. ( Fmla ` suc d ) <-> b e. ( Fmla ` suc suc c ) ) ) | 
						
							| 23 | 21 22 | anbi12d |  |-  ( d = suc c -> ( ( a e. ( Fmla ` suc d ) /\ b e. ( Fmla ` suc d ) ) <-> ( a e. ( Fmla ` suc suc c ) /\ b e. ( Fmla ` suc suc c ) ) ) ) | 
						
							| 24 | 20 23 | imbi12d |  |-  ( d = suc c -> ( ( ( a |g b ) e. ( Fmla ` suc d ) -> ( a e. ( Fmla ` suc d ) /\ b e. ( Fmla ` suc d ) ) ) <-> ( ( a |g b ) e. ( Fmla ` suc suc c ) -> ( a e. ( Fmla ` suc suc c ) /\ b e. ( Fmla ` suc suc c ) ) ) ) ) | 
						
							| 25 |  | suceq |  |-  ( d = x -> suc d = suc x ) | 
						
							| 26 | 25 | fveq2d |  |-  ( d = x -> ( Fmla ` suc d ) = ( Fmla ` suc x ) ) | 
						
							| 27 | 26 | eleq2d |  |-  ( d = x -> ( ( a |g b ) e. ( Fmla ` suc d ) <-> ( a |g b ) e. ( Fmla ` suc x ) ) ) | 
						
							| 28 | 26 | eleq2d |  |-  ( d = x -> ( a e. ( Fmla ` suc d ) <-> a e. ( Fmla ` suc x ) ) ) | 
						
							| 29 | 26 | eleq2d |  |-  ( d = x -> ( b e. ( Fmla ` suc d ) <-> b e. ( Fmla ` suc x ) ) ) | 
						
							| 30 | 28 29 | anbi12d |  |-  ( d = x -> ( ( a e. ( Fmla ` suc d ) /\ b e. ( Fmla ` suc d ) ) <-> ( a e. ( Fmla ` suc x ) /\ b e. ( Fmla ` suc x ) ) ) ) | 
						
							| 31 | 27 30 | imbi12d |  |-  ( d = x -> ( ( ( a |g b ) e. ( Fmla ` suc d ) -> ( a e. ( Fmla ` suc d ) /\ b e. ( Fmla ` suc d ) ) ) <-> ( ( a |g b ) e. ( Fmla ` suc x ) -> ( a e. ( Fmla ` suc x ) /\ b e. ( Fmla ` suc x ) ) ) ) ) | 
						
							| 32 |  | peano1 |  |-  (/) e. _om | 
						
							| 33 |  | ovex |  |-  ( a |g b ) e. _V | 
						
							| 34 |  | isfmlasuc |  |-  ( ( (/) e. _om /\ ( a |g b ) e. _V ) -> ( ( a |g b ) e. ( Fmla ` suc (/) ) <-> ( ( a |g b ) e. ( Fmla ` (/) ) \/ E. u e. ( Fmla ` (/) ) ( E. v e. ( Fmla ` (/) ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) ) ) ) | 
						
							| 35 | 32 33 34 | mp2an |  |-  ( ( a |g b ) e. ( Fmla ` suc (/) ) <-> ( ( a |g b ) e. ( Fmla ` (/) ) \/ E. u e. ( Fmla ` (/) ) ( E. v e. ( Fmla ` (/) ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) ) ) | 
						
							| 36 |  | eqeq1 |  |-  ( x = ( a |g b ) -> ( x = ( i e.g j ) <-> ( a |g b ) = ( i e.g j ) ) ) | 
						
							| 37 | 36 | 2rexbidv |  |-  ( x = ( a |g b ) -> ( E. i e. _om E. j e. _om x = ( i e.g j ) <-> E. i e. _om E. j e. _om ( a |g b ) = ( i e.g j ) ) ) | 
						
							| 38 |  | fmla0 |  |-  ( Fmla ` (/) ) = { x e. _V | E. i e. _om E. j e. _om x = ( i e.g j ) } | 
						
							| 39 | 37 38 | elrab2 |  |-  ( ( a |g b ) e. ( Fmla ` (/) ) <-> ( ( a |g b ) e. _V /\ E. i e. _om E. j e. _om ( a |g b ) = ( i e.g j ) ) ) | 
						
							| 40 |  | gonafv |  |-  ( ( a e. _V /\ b e. _V ) -> ( a |g b ) = <. 1o , <. a , b >. >. ) | 
						
							| 41 | 40 | el2v |  |-  ( a |g b ) = <. 1o , <. a , b >. >. | 
						
							| 42 | 41 | a1i |  |-  ( ( i e. _om /\ j e. _om ) -> ( a |g b ) = <. 1o , <. a , b >. >. ) | 
						
							| 43 |  | goel |  |-  ( ( i e. _om /\ j e. _om ) -> ( i e.g j ) = <. (/) , <. i , j >. >. ) | 
						
							| 44 | 42 43 | eqeq12d |  |-  ( ( i e. _om /\ j e. _om ) -> ( ( a |g b ) = ( i e.g j ) <-> <. 1o , <. a , b >. >. = <. (/) , <. i , j >. >. ) ) | 
						
							| 45 |  | 1oex |  |-  1o e. _V | 
						
							| 46 |  | opex |  |-  <. a , b >. e. _V | 
						
							| 47 | 45 46 | opth |  |-  ( <. 1o , <. a , b >. >. = <. (/) , <. i , j >. >. <-> ( 1o = (/) /\ <. a , b >. = <. i , j >. ) ) | 
						
							| 48 |  | 1n0 |  |-  1o =/= (/) | 
						
							| 49 |  | eqneqall |  |-  ( 1o = (/) -> ( 1o =/= (/) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 50 | 48 49 | mpi |  |-  ( 1o = (/) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 51 | 50 | adantr |  |-  ( ( 1o = (/) /\ <. a , b >. = <. i , j >. ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 52 | 47 51 | sylbi |  |-  ( <. 1o , <. a , b >. >. = <. (/) , <. i , j >. >. -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 53 | 44 52 | biimtrdi |  |-  ( ( i e. _om /\ j e. _om ) -> ( ( a |g b ) = ( i e.g j ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 54 | 53 | rexlimdva |  |-  ( i e. _om -> ( E. j e. _om ( a |g b ) = ( i e.g j ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 55 | 54 | rexlimiv |  |-  ( E. i e. _om E. j e. _om ( a |g b ) = ( i e.g j ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 56 | 55 | adantl |  |-  ( ( ( a |g b ) e. _V /\ E. i e. _om E. j e. _om ( a |g b ) = ( i e.g j ) ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 57 | 39 56 | sylbi |  |-  ( ( a |g b ) e. ( Fmla ` (/) ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 58 | 41 | a1i |  |-  ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) -> ( a |g b ) = <. 1o , <. a , b >. >. ) | 
						
							| 59 |  | gonafv |  |-  ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) -> ( u |g v ) = <. 1o , <. u , v >. >. ) | 
						
							| 60 | 58 59 | eqeq12d |  |-  ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) -> ( ( a |g b ) = ( u |g v ) <-> <. 1o , <. a , b >. >. = <. 1o , <. u , v >. >. ) ) | 
						
							| 61 | 45 46 | opth |  |-  ( <. 1o , <. a , b >. >. = <. 1o , <. u , v >. >. <-> ( 1o = 1o /\ <. a , b >. = <. u , v >. ) ) | 
						
							| 62 |  | vex |  |-  a e. _V | 
						
							| 63 |  | vex |  |-  b e. _V | 
						
							| 64 | 62 63 | opth |  |-  ( <. a , b >. = <. u , v >. <-> ( a = u /\ b = v ) ) | 
						
							| 65 |  | simpl |  |-  ( ( a = u /\ b = v ) -> a = u ) | 
						
							| 66 | 65 | equcomd |  |-  ( ( a = u /\ b = v ) -> u = a ) | 
						
							| 67 | 66 | eleq1d |  |-  ( ( a = u /\ b = v ) -> ( u e. ( Fmla ` (/) ) <-> a e. ( Fmla ` (/) ) ) ) | 
						
							| 68 |  | simpr |  |-  ( ( a = u /\ b = v ) -> b = v ) | 
						
							| 69 | 68 | equcomd |  |-  ( ( a = u /\ b = v ) -> v = b ) | 
						
							| 70 | 69 | eleq1d |  |-  ( ( a = u /\ b = v ) -> ( v e. ( Fmla ` (/) ) <-> b e. ( Fmla ` (/) ) ) ) | 
						
							| 71 | 67 70 | anbi12d |  |-  ( ( a = u /\ b = v ) -> ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) <-> ( a e. ( Fmla ` (/) ) /\ b e. ( Fmla ` (/) ) ) ) ) | 
						
							| 72 | 64 71 | sylbi |  |-  ( <. a , b >. = <. u , v >. -> ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) <-> ( a e. ( Fmla ` (/) ) /\ b e. ( Fmla ` (/) ) ) ) ) | 
						
							| 73 | 72 | adantl |  |-  ( ( 1o = 1o /\ <. a , b >. = <. u , v >. ) -> ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) <-> ( a e. ( Fmla ` (/) ) /\ b e. ( Fmla ` (/) ) ) ) ) | 
						
							| 74 | 61 73 | sylbi |  |-  ( <. 1o , <. a , b >. >. = <. 1o , <. u , v >. >. -> ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) <-> ( a e. ( Fmla ` (/) ) /\ b e. ( Fmla ` (/) ) ) ) ) | 
						
							| 75 |  | fmlasssuc |  |-  ( (/) e. _om -> ( Fmla ` (/) ) C_ ( Fmla ` suc (/) ) ) | 
						
							| 76 | 32 75 | ax-mp |  |-  ( Fmla ` (/) ) C_ ( Fmla ` suc (/) ) | 
						
							| 77 | 76 | sseli |  |-  ( a e. ( Fmla ` (/) ) -> a e. ( Fmla ` suc (/) ) ) | 
						
							| 78 | 76 | sseli |  |-  ( b e. ( Fmla ` (/) ) -> b e. ( Fmla ` suc (/) ) ) | 
						
							| 79 | 77 78 | anim12i |  |-  ( ( a e. ( Fmla ` (/) ) /\ b e. ( Fmla ` (/) ) ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 80 | 74 79 | biimtrdi |  |-  ( <. 1o , <. a , b >. >. = <. 1o , <. u , v >. >. -> ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 81 | 80 | com12 |  |-  ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) -> ( <. 1o , <. a , b >. >. = <. 1o , <. u , v >. >. -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 82 | 60 81 | sylbid |  |-  ( ( u e. ( Fmla ` (/) ) /\ v e. ( Fmla ` (/) ) ) -> ( ( a |g b ) = ( u |g v ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 83 | 82 | rexlimdva |  |-  ( u e. ( Fmla ` (/) ) -> ( E. v e. ( Fmla ` (/) ) ( a |g b ) = ( u |g v ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 84 |  | gonanegoal |  |-  ( a |g b ) =/= A.g i u | 
						
							| 85 |  | eqneqall |  |-  ( ( a |g b ) = A.g i u -> ( ( a |g b ) =/= A.g i u -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 86 | 84 85 | mpi |  |-  ( ( a |g b ) = A.g i u -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 87 | 86 | a1i |  |-  ( ( u e. ( Fmla ` (/) ) /\ i e. _om ) -> ( ( a |g b ) = A.g i u -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 88 | 87 | rexlimdva |  |-  ( u e. ( Fmla ` (/) ) -> ( E. i e. _om ( a |g b ) = A.g i u -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 89 | 83 88 | jaod |  |-  ( u e. ( Fmla ` (/) ) -> ( ( E. v e. ( Fmla ` (/) ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) ) | 
						
							| 90 | 89 | rexlimiv |  |-  ( E. u e. ( Fmla ` (/) ) ( E. v e. ( Fmla ` (/) ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 91 | 57 90 | jaoi |  |-  ( ( ( a |g b ) e. ( Fmla ` (/) ) \/ E. u e. ( Fmla ` (/) ) ( E. v e. ( Fmla ` (/) ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 92 | 35 91 | sylbi |  |-  ( ( a |g b ) e. ( Fmla ` suc (/) ) -> ( a e. ( Fmla ` suc (/) ) /\ b e. ( Fmla ` suc (/) ) ) ) | 
						
							| 93 |  | gonarlem |  |-  ( c e. _om -> ( ( ( a |g b ) e. ( Fmla ` suc c ) -> ( a e. ( Fmla ` suc c ) /\ b e. ( Fmla ` suc c ) ) ) -> ( ( a |g b ) e. ( Fmla ` suc suc c ) -> ( a e. ( Fmla ` suc suc c ) /\ b e. ( Fmla ` suc suc c ) ) ) ) ) | 
						
							| 94 | 10 17 24 31 92 93 | finds |  |-  ( x e. _om -> ( ( a |g b ) e. ( Fmla ` suc x ) -> ( a e. ( Fmla ` suc x ) /\ b e. ( Fmla ` suc x ) ) ) ) | 
						
							| 95 | 94 | adantr |  |-  ( ( x e. _om /\ N = suc x ) -> ( ( a |g b ) e. ( Fmla ` suc x ) -> ( a e. ( Fmla ` suc x ) /\ b e. ( Fmla ` suc x ) ) ) ) | 
						
							| 96 |  | fveq2 |  |-  ( N = suc x -> ( Fmla ` N ) = ( Fmla ` suc x ) ) | 
						
							| 97 | 96 | eleq2d |  |-  ( N = suc x -> ( ( a |g b ) e. ( Fmla ` N ) <-> ( a |g b ) e. ( Fmla ` suc x ) ) ) | 
						
							| 98 | 96 | eleq2d |  |-  ( N = suc x -> ( a e. ( Fmla ` N ) <-> a e. ( Fmla ` suc x ) ) ) | 
						
							| 99 | 96 | eleq2d |  |-  ( N = suc x -> ( b e. ( Fmla ` N ) <-> b e. ( Fmla ` suc x ) ) ) | 
						
							| 100 | 98 99 | anbi12d |  |-  ( N = suc x -> ( ( a e. ( Fmla ` N ) /\ b e. ( Fmla ` N ) ) <-> ( a e. ( Fmla ` suc x ) /\ b e. ( Fmla ` suc x ) ) ) ) | 
						
							| 101 | 97 100 | imbi12d |  |-  ( N = suc x -> ( ( ( a |g b ) e. ( Fmla ` N ) -> ( a e. ( Fmla ` N ) /\ b e. ( Fmla ` N ) ) ) <-> ( ( a |g b ) e. ( Fmla ` suc x ) -> ( a e. ( Fmla ` suc x ) /\ b e. ( Fmla ` suc x ) ) ) ) ) | 
						
							| 102 | 101 | adantl |  |-  ( ( x e. _om /\ N = suc x ) -> ( ( ( a |g b ) e. ( Fmla ` N ) -> ( a e. ( Fmla ` N ) /\ b e. ( Fmla ` N ) ) ) <-> ( ( a |g b ) e. ( Fmla ` suc x ) -> ( a e. ( Fmla ` suc x ) /\ b e. ( Fmla ` suc x ) ) ) ) ) | 
						
							| 103 | 95 102 | mpbird |  |-  ( ( x e. _om /\ N = suc x ) -> ( ( a |g b ) e. ( Fmla ` N ) -> ( a e. ( Fmla ` N ) /\ b e. ( Fmla ` N ) ) ) ) | 
						
							| 104 | 103 | rexlimiva |  |-  ( E. x e. _om N = suc x -> ( ( a |g b ) e. ( Fmla ` N ) -> ( a e. ( Fmla ` N ) /\ b e. ( Fmla ` N ) ) ) ) | 
						
							| 105 | 3 104 | syl |  |-  ( ( N e. _om /\ N =/= (/) ) -> ( ( a |g b ) e. ( Fmla ` N ) -> ( a e. ( Fmla ` N ) /\ b e. ( Fmla ` N ) ) ) ) | 
						
							| 106 | 105 | impancom |  |-  ( ( N e. _om /\ ( a |g b ) e. ( Fmla ` N ) ) -> ( N =/= (/) -> ( a e. ( Fmla ` N ) /\ b e. ( Fmla ` N ) ) ) ) | 
						
							| 107 | 2 106 | mpd |  |-  ( ( N e. _om /\ ( a |g b ) e. ( Fmla ` N ) ) -> ( a e. ( Fmla ` N ) /\ b e. ( Fmla ` N ) ) ) |