| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-ltpq |  |-  . | ( ( x e. ( N. X. N. ) /\ y e. ( N. X. N. ) ) /\ ( ( 1st ` x ) .N ( 2nd ` y ) )  | 
						
							| 2 |  | opabssxp |  |-  { <. x , y >. | ( ( x e. ( N. X. N. ) /\ y e. ( N. X. N. ) ) /\ ( ( 1st ` x ) .N ( 2nd ` y ) )  | 
						
							| 3 | 1 2 | eqsstri |  |-   | 
						
							| 4 | 3 | brel |  |-  ( A  ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) ) | 
						
							| 5 |  | ltrelnq |  |-   | 
						
							| 6 | 5 | brel |  |-  ( ( /Q ` A )  ( ( /Q ` A ) e. Q. /\ ( /Q ` B ) e. Q. ) ) | 
						
							| 7 |  | elpqn |  |-  ( ( /Q ` A ) e. Q. -> ( /Q ` A ) e. ( N. X. N. ) ) | 
						
							| 8 |  | elpqn |  |-  ( ( /Q ` B ) e. Q. -> ( /Q ` B ) e. ( N. X. N. ) ) | 
						
							| 9 |  | nqerf |  |-  /Q : ( N. X. N. ) --> Q. | 
						
							| 10 | 9 | fdmi |  |-  dom /Q = ( N. X. N. ) | 
						
							| 11 |  | 0nelxp |  |-  -. (/) e. ( N. X. N. ) | 
						
							| 12 | 10 11 | ndmfvrcl |  |-  ( ( /Q ` A ) e. ( N. X. N. ) -> A e. ( N. X. N. ) ) | 
						
							| 13 | 10 11 | ndmfvrcl |  |-  ( ( /Q ` B ) e. ( N. X. N. ) -> B e. ( N. X. N. ) ) | 
						
							| 14 | 12 13 | anim12i |  |-  ( ( ( /Q ` A ) e. ( N. X. N. ) /\ ( /Q ` B ) e. ( N. X. N. ) ) -> ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) ) | 
						
							| 15 | 7 8 14 | syl2an |  |-  ( ( ( /Q ` A ) e. Q. /\ ( /Q ` B ) e. Q. ) -> ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) ) | 
						
							| 16 | 6 15 | syl |  |-  ( ( /Q ` A )  ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) ) | 
						
							| 17 |  | xp1st |  |-  ( A e. ( N. X. N. ) -> ( 1st ` A ) e. N. ) | 
						
							| 18 |  | xp2nd |  |-  ( B e. ( N. X. N. ) -> ( 2nd ` B ) e. N. ) | 
						
							| 19 |  | mulclpi |  |-  ( ( ( 1st ` A ) e. N. /\ ( 2nd ` B ) e. N. ) -> ( ( 1st ` A ) .N ( 2nd ` B ) ) e. N. ) | 
						
							| 20 | 17 18 19 | syl2an |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( 1st ` A ) .N ( 2nd ` B ) ) e. N. ) | 
						
							| 21 |  | ltmpi |  |-  ( ( ( 1st ` A ) .N ( 2nd ` B ) ) e. N. -> ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) )  ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) )  | 
						
							| 22 | 20 21 | syl |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) )  ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) )  | 
						
							| 23 |  | nqercl |  |-  ( A e. ( N. X. N. ) -> ( /Q ` A ) e. Q. ) | 
						
							| 24 |  | nqercl |  |-  ( B e. ( N. X. N. ) -> ( /Q ` B ) e. Q. ) | 
						
							| 25 |  | ordpinq |  |-  ( ( ( /Q ` A ) e. Q. /\ ( /Q ` B ) e. Q. ) -> ( ( /Q ` A )  ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) )  | 
						
							| 26 | 23 24 25 | syl2an |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( /Q ` A )  ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) )  | 
						
							| 27 |  | 1st2nd2 |  |-  ( A e. ( N. X. N. ) -> A = <. ( 1st ` A ) , ( 2nd ` A ) >. ) | 
						
							| 28 |  | 1st2nd2 |  |-  ( B e. ( N. X. N. ) -> B = <. ( 1st ` B ) , ( 2nd ` B ) >. ) | 
						
							| 29 | 27 28 | breqan12d |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( A  <. ( 1st ` A ) , ( 2nd ` A ) >. . ) ) | 
						
							| 30 |  | ordpipq |  |-  ( <. ( 1st ` A ) , ( 2nd ` A ) >. . <-> ( ( 1st ` A ) .N ( 2nd ` B ) )  | 
						
							| 31 | 29 30 | bitrdi |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( A  ( ( 1st ` A ) .N ( 2nd ` B ) )  | 
						
							| 32 |  | xp1st |  |-  ( ( /Q ` A ) e. ( N. X. N. ) -> ( 1st ` ( /Q ` A ) ) e. N. ) | 
						
							| 33 | 23 7 32 | 3syl |  |-  ( A e. ( N. X. N. ) -> ( 1st ` ( /Q ` A ) ) e. N. ) | 
						
							| 34 |  | xp2nd |  |-  ( ( /Q ` B ) e. ( N. X. N. ) -> ( 2nd ` ( /Q ` B ) ) e. N. ) | 
						
							| 35 | 24 8 34 | 3syl |  |-  ( B e. ( N. X. N. ) -> ( 2nd ` ( /Q ` B ) ) e. N. ) | 
						
							| 36 |  | mulclpi |  |-  ( ( ( 1st ` ( /Q ` A ) ) e. N. /\ ( 2nd ` ( /Q ` B ) ) e. N. ) -> ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) e. N. ) | 
						
							| 37 | 33 35 36 | syl2an |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) e. N. ) | 
						
							| 38 |  | ltmpi |  |-  ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) e. N. -> ( ( ( 1st ` A ) .N ( 2nd ` B ) )  ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) .N ( ( 1st ` A ) .N ( 2nd ` B ) ) )  | 
						
							| 39 | 37 38 | syl |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( ( 1st ` A ) .N ( 2nd ` B ) )  ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) .N ( ( 1st ` A ) .N ( 2nd ` B ) ) )  | 
						
							| 40 |  | mulcompi |  |-  ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) .N ( ( 1st ` A ) .N ( 2nd ` B ) ) ) = ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) ) | 
						
							| 41 | 40 | a1i |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) .N ( ( 1st ` A ) .N ( 2nd ` B ) ) ) = ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) ) ) | 
						
							| 42 |  | nqerrel |  |-  ( A e. ( N. X. N. ) -> A ~Q ( /Q ` A ) ) | 
						
							| 43 | 23 7 | syl |  |-  ( A e. ( N. X. N. ) -> ( /Q ` A ) e. ( N. X. N. ) ) | 
						
							| 44 |  | enqbreq2 |  |-  ( ( A e. ( N. X. N. ) /\ ( /Q ` A ) e. ( N. X. N. ) ) -> ( A ~Q ( /Q ` A ) <-> ( ( 1st ` A ) .N ( 2nd ` ( /Q ` A ) ) ) = ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` A ) ) ) ) | 
						
							| 45 | 43 44 | mpdan |  |-  ( A e. ( N. X. N. ) -> ( A ~Q ( /Q ` A ) <-> ( ( 1st ` A ) .N ( 2nd ` ( /Q ` A ) ) ) = ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` A ) ) ) ) | 
						
							| 46 | 42 45 | mpbid |  |-  ( A e. ( N. X. N. ) -> ( ( 1st ` A ) .N ( 2nd ` ( /Q ` A ) ) ) = ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` A ) ) ) | 
						
							| 47 | 46 | eqcomd |  |-  ( A e. ( N. X. N. ) -> ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` A ) ) = ( ( 1st ` A ) .N ( 2nd ` ( /Q ` A ) ) ) ) | 
						
							| 48 |  | nqerrel |  |-  ( B e. ( N. X. N. ) -> B ~Q ( /Q ` B ) ) | 
						
							| 49 | 24 8 | syl |  |-  ( B e. ( N. X. N. ) -> ( /Q ` B ) e. ( N. X. N. ) ) | 
						
							| 50 |  | enqbreq2 |  |-  ( ( B e. ( N. X. N. ) /\ ( /Q ` B ) e. ( N. X. N. ) ) -> ( B ~Q ( /Q ` B ) <-> ( ( 1st ` B ) .N ( 2nd ` ( /Q ` B ) ) ) = ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` B ) ) ) ) | 
						
							| 51 | 49 50 | mpdan |  |-  ( B e. ( N. X. N. ) -> ( B ~Q ( /Q ` B ) <-> ( ( 1st ` B ) .N ( 2nd ` ( /Q ` B ) ) ) = ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` B ) ) ) ) | 
						
							| 52 | 48 51 | mpbid |  |-  ( B e. ( N. X. N. ) -> ( ( 1st ` B ) .N ( 2nd ` ( /Q ` B ) ) ) = ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` B ) ) ) | 
						
							| 53 | 47 52 | oveqan12d |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` A ) ) .N ( ( 1st ` B ) .N ( 2nd ` ( /Q ` B ) ) ) ) = ( ( ( 1st ` A ) .N ( 2nd ` ( /Q ` A ) ) ) .N ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` B ) ) ) ) | 
						
							| 54 |  | mulcompi |  |-  ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) .N ( ( 1st ` B ) .N ( 2nd ` A ) ) ) = ( ( ( 1st ` B ) .N ( 2nd ` A ) ) .N ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) ) | 
						
							| 55 |  | fvex |  |-  ( 1st ` B ) e. _V | 
						
							| 56 |  | fvex |  |-  ( 2nd ` A ) e. _V | 
						
							| 57 |  | fvex |  |-  ( 1st ` ( /Q ` A ) ) e. _V | 
						
							| 58 |  | mulcompi |  |-  ( x .N y ) = ( y .N x ) | 
						
							| 59 |  | mulasspi |  |-  ( ( x .N y ) .N z ) = ( x .N ( y .N z ) ) | 
						
							| 60 |  | fvex |  |-  ( 2nd ` ( /Q ` B ) ) e. _V | 
						
							| 61 | 55 56 57 58 59 60 | caov411 |  |-  ( ( ( 1st ` B ) .N ( 2nd ` A ) ) .N ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) ) = ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` A ) ) .N ( ( 1st ` B ) .N ( 2nd ` ( /Q ` B ) ) ) ) | 
						
							| 62 | 54 61 | eqtri |  |-  ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) .N ( ( 1st ` B ) .N ( 2nd ` A ) ) ) = ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` A ) ) .N ( ( 1st ` B ) .N ( 2nd ` ( /Q ` B ) ) ) ) | 
						
							| 63 |  | mulcompi |  |-  ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` ( /Q ` A ) ) ) ) = ( ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` ( /Q ` A ) ) ) .N ( ( 1st ` A ) .N ( 2nd ` B ) ) ) | 
						
							| 64 |  | fvex |  |-  ( 1st ` ( /Q ` B ) ) e. _V | 
						
							| 65 |  | fvex |  |-  ( 2nd ` ( /Q ` A ) ) e. _V | 
						
							| 66 |  | fvex |  |-  ( 1st ` A ) e. _V | 
						
							| 67 |  | fvex |  |-  ( 2nd ` B ) e. _V | 
						
							| 68 | 64 65 66 58 59 67 | caov411 |  |-  ( ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` ( /Q ` A ) ) ) .N ( ( 1st ` A ) .N ( 2nd ` B ) ) ) = ( ( ( 1st ` A ) .N ( 2nd ` ( /Q ` A ) ) ) .N ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` B ) ) ) | 
						
							| 69 | 63 68 | eqtri |  |-  ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` ( /Q ` A ) ) ) ) = ( ( ( 1st ` A ) .N ( 2nd ` ( /Q ` A ) ) ) .N ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` B ) ) ) | 
						
							| 70 | 53 62 69 | 3eqtr4g |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) .N ( ( 1st ` B ) .N ( 2nd ` A ) ) ) = ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` B ) ) .N ( 2nd ` ( /Q ` A ) ) ) ) ) | 
						
							| 71 | 41 70 | breq12d |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( ( ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) .N ( ( 1st ` A ) .N ( 2nd ` B ) ) )  ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) )  | 
						
							| 72 | 31 39 71 | 3bitrd |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( A  ( ( ( 1st ` A ) .N ( 2nd ` B ) ) .N ( ( 1st ` ( /Q ` A ) ) .N ( 2nd ` ( /Q ` B ) ) ) )  | 
						
							| 73 | 22 26 72 | 3bitr4rd |  |-  ( ( A e. ( N. X. N. ) /\ B e. ( N. X. N. ) ) -> ( A  ( /Q ` A )  | 
						
							| 74 | 4 16 73 | pm5.21nii |  |-  ( A  ( /Q ` A )  |