| Step | Hyp | Ref | Expression | 
						
							| 1 |  | peano2 |  |-  ( N e. _om -> suc N e. _om ) | 
						
							| 2 |  | ovexd |  |-  ( N e. _om -> ( a |g b ) e. _V ) | 
						
							| 3 |  | isfmlasuc |  |-  ( ( suc N e. _om /\ ( a |g b ) e. _V ) -> ( ( a |g b ) e. ( Fmla ` suc suc N ) <-> ( ( a |g b ) e. ( Fmla ` suc N ) \/ E. u e. ( Fmla ` suc N ) ( E. v e. ( Fmla ` suc N ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) ) ) ) | 
						
							| 4 | 1 2 3 | syl2anc |  |-  ( N e. _om -> ( ( a |g b ) e. ( Fmla ` suc suc N ) <-> ( ( a |g b ) e. ( Fmla ` suc N ) \/ E. u e. ( Fmla ` suc N ) ( E. v e. ( Fmla ` suc N ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) ) ) ) | 
						
							| 5 | 4 | adantr |  |-  ( ( N e. _om /\ ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) ) -> ( ( a |g b ) e. ( Fmla ` suc suc N ) <-> ( ( a |g b ) e. ( Fmla ` suc N ) \/ E. u e. ( Fmla ` suc N ) ( E. v e. ( Fmla ` suc N ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) ) ) ) | 
						
							| 6 |  | fmlasssuc |  |-  ( suc N e. _om -> ( Fmla ` suc N ) C_ ( Fmla ` suc suc N ) ) | 
						
							| 7 | 1 6 | syl |  |-  ( N e. _om -> ( Fmla ` suc N ) C_ ( Fmla ` suc suc N ) ) | 
						
							| 8 | 7 | sseld |  |-  ( N e. _om -> ( a e. ( Fmla ` suc N ) -> a e. ( Fmla ` suc suc N ) ) ) | 
						
							| 9 | 7 | sseld |  |-  ( N e. _om -> ( b e. ( Fmla ` suc N ) -> b e. ( Fmla ` suc suc N ) ) ) | 
						
							| 10 | 8 9 | anim12d |  |-  ( N e. _om -> ( ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 11 | 10 | com12 |  |-  ( ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) -> ( N e. _om -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 12 | 11 | imim2i |  |-  ( ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) -> ( ( a |g b ) e. ( Fmla ` suc N ) -> ( N e. _om -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) ) | 
						
							| 13 | 12 | com23 |  |-  ( ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) -> ( N e. _om -> ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) ) | 
						
							| 14 | 13 | impcom |  |-  ( ( N e. _om /\ ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) ) -> ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 15 |  | gonafv |  |-  ( ( a e. _V /\ b e. _V ) -> ( a |g b ) = <. 1o , <. a , b >. >. ) | 
						
							| 16 | 15 | el2v |  |-  ( a |g b ) = <. 1o , <. a , b >. >. | 
						
							| 17 | 16 | a1i |  |-  ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) -> ( a |g b ) = <. 1o , <. a , b >. >. ) | 
						
							| 18 |  | gonafv |  |-  ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) -> ( u |g v ) = <. 1o , <. u , v >. >. ) | 
						
							| 19 | 17 18 | eqeq12d |  |-  ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) -> ( ( a |g b ) = ( u |g v ) <-> <. 1o , <. a , b >. >. = <. 1o , <. u , v >. >. ) ) | 
						
							| 20 |  | 1oex |  |-  1o e. _V | 
						
							| 21 |  | opex |  |-  <. a , b >. e. _V | 
						
							| 22 | 20 21 | opth |  |-  ( <. 1o , <. a , b >. >. = <. 1o , <. u , v >. >. <-> ( 1o = 1o /\ <. a , b >. = <. u , v >. ) ) | 
						
							| 23 | 19 22 | bitrdi |  |-  ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) -> ( ( a |g b ) = ( u |g v ) <-> ( 1o = 1o /\ <. a , b >. = <. u , v >. ) ) ) | 
						
							| 24 | 23 | adantll |  |-  ( ( ( N e. _om /\ u e. ( Fmla ` suc N ) ) /\ v e. ( Fmla ` suc N ) ) -> ( ( a |g b ) = ( u |g v ) <-> ( 1o = 1o /\ <. a , b >. = <. u , v >. ) ) ) | 
						
							| 25 |  | vex |  |-  a e. _V | 
						
							| 26 |  | vex |  |-  b e. _V | 
						
							| 27 | 25 26 | opth |  |-  ( <. a , b >. = <. u , v >. <-> ( a = u /\ b = v ) ) | 
						
							| 28 |  | eleq1w |  |-  ( u = a -> ( u e. ( Fmla ` suc N ) <-> a e. ( Fmla ` suc N ) ) ) | 
						
							| 29 | 28 | equcoms |  |-  ( a = u -> ( u e. ( Fmla ` suc N ) <-> a e. ( Fmla ` suc N ) ) ) | 
						
							| 30 |  | eleq1w |  |-  ( v = b -> ( v e. ( Fmla ` suc N ) <-> b e. ( Fmla ` suc N ) ) ) | 
						
							| 31 | 30 | equcoms |  |-  ( b = v -> ( v e. ( Fmla ` suc N ) <-> b e. ( Fmla ` suc N ) ) ) | 
						
							| 32 | 29 31 | bi2anan9 |  |-  ( ( a = u /\ b = v ) -> ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) <-> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) ) | 
						
							| 33 | 32 11 | biimtrdi |  |-  ( ( a = u /\ b = v ) -> ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) -> ( N e. _om -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) ) | 
						
							| 34 | 27 33 | sylbi |  |-  ( <. a , b >. = <. u , v >. -> ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) -> ( N e. _om -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) ) | 
						
							| 35 | 34 | adantl |  |-  ( ( 1o = 1o /\ <. a , b >. = <. u , v >. ) -> ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) -> ( N e. _om -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) ) | 
						
							| 36 | 35 | com13 |  |-  ( N e. _om -> ( ( u e. ( Fmla ` suc N ) /\ v e. ( Fmla ` suc N ) ) -> ( ( 1o = 1o /\ <. a , b >. = <. u , v >. ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) ) | 
						
							| 37 | 36 | impl |  |-  ( ( ( N e. _om /\ u e. ( Fmla ` suc N ) ) /\ v e. ( Fmla ` suc N ) ) -> ( ( 1o = 1o /\ <. a , b >. = <. u , v >. ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 38 | 24 37 | sylbid |  |-  ( ( ( N e. _om /\ u e. ( Fmla ` suc N ) ) /\ v e. ( Fmla ` suc N ) ) -> ( ( a |g b ) = ( u |g v ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 39 | 38 | rexlimdva |  |-  ( ( N e. _om /\ u e. ( Fmla ` suc N ) ) -> ( E. v e. ( Fmla ` suc N ) ( a |g b ) = ( u |g v ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 40 |  | gonanegoal |  |-  ( a |g b ) =/= A.g i u | 
						
							| 41 |  | eqneqall |  |-  ( ( a |g b ) = A.g i u -> ( ( a |g b ) =/= A.g i u -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 42 | 40 41 | mpi |  |-  ( ( a |g b ) = A.g i u -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) | 
						
							| 43 | 42 | a1i |  |-  ( ( ( N e. _om /\ u e. ( Fmla ` suc N ) ) /\ i e. _om ) -> ( ( a |g b ) = A.g i u -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 44 | 43 | rexlimdva |  |-  ( ( N e. _om /\ u e. ( Fmla ` suc N ) ) -> ( E. i e. _om ( a |g b ) = A.g i u -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 45 | 39 44 | jaod |  |-  ( ( N e. _om /\ u e. ( Fmla ` suc N ) ) -> ( ( E. v e. ( Fmla ` suc N ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 46 | 45 | rexlimdva |  |-  ( N e. _om -> ( E. u e. ( Fmla ` suc N ) ( E. v e. ( Fmla ` suc N ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 47 | 46 | adantr |  |-  ( ( N e. _om /\ ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) ) -> ( E. u e. ( Fmla ` suc N ) ( E. v e. ( Fmla ` suc N ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 48 | 14 47 | jaod |  |-  ( ( N e. _om /\ ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) ) -> ( ( ( a |g b ) e. ( Fmla ` suc N ) \/ E. u e. ( Fmla ` suc N ) ( E. v e. ( Fmla ` suc N ) ( a |g b ) = ( u |g v ) \/ E. i e. _om ( a |g b ) = A.g i u ) ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 49 | 5 48 | sylbid |  |-  ( ( N e. _om /\ ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) ) -> ( ( a |g b ) e. ( Fmla ` suc suc N ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) | 
						
							| 50 | 49 | ex |  |-  ( N e. _om -> ( ( ( a |g b ) e. ( Fmla ` suc N ) -> ( a e. ( Fmla ` suc N ) /\ b e. ( Fmla ` suc N ) ) ) -> ( ( a |g b ) e. ( Fmla ` suc suc N ) -> ( a e. ( Fmla ` suc suc N ) /\ b e. ( Fmla ` suc suc N ) ) ) ) ) |