| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rrx2plord.o |  |-  O = { <. x , y >. | ( ( x e. R /\ y e. R ) /\ ( ( x ` 1 ) < ( y ` 1 ) \/ ( ( x ` 1 ) = ( y ` 1 ) /\ ( x ` 2 ) < ( y ` 2 ) ) ) ) } | 
						
							| 2 |  | rrx2plord2.r |  |-  R = ( RR ^m { 1 , 2 } ) | 
						
							| 3 |  | ltso |  |-  < Or RR | 
						
							| 4 |  | eqid |  |-  { <. x , y >. | ( ( x e. ( RR X. RR ) /\ y e. ( RR X. RR ) ) /\ ( ( 1st ` x ) < ( 1st ` y ) \/ ( ( 1st ` x ) = ( 1st ` y ) /\ ( 2nd ` x ) < ( 2nd ` y ) ) ) ) } = { <. x , y >. | ( ( x e. ( RR X. RR ) /\ y e. ( RR X. RR ) ) /\ ( ( 1st ` x ) < ( 1st ` y ) \/ ( ( 1st ` x ) = ( 1st ` y ) /\ ( 2nd ` x ) < ( 2nd ` y ) ) ) ) } | 
						
							| 5 | 4 | soxp |  |-  ( ( < Or RR /\ < Or RR ) -> { <. x , y >. | ( ( x e. ( RR X. RR ) /\ y e. ( RR X. RR ) ) /\ ( ( 1st ` x ) < ( 1st ` y ) \/ ( ( 1st ` x ) = ( 1st ` y ) /\ ( 2nd ` x ) < ( 2nd ` y ) ) ) ) } Or ( RR X. RR ) ) | 
						
							| 6 | 3 3 5 | mp2an |  |-  { <. x , y >. | ( ( x e. ( RR X. RR ) /\ y e. ( RR X. RR ) ) /\ ( ( 1st ` x ) < ( 1st ` y ) \/ ( ( 1st ` x ) = ( 1st ` y ) /\ ( 2nd ` x ) < ( 2nd ` y ) ) ) ) } Or ( RR X. RR ) | 
						
							| 7 |  | eqid |  |-  ( x e. RR , y e. RR |-> { <. 1 , x >. , <. 2 , y >. } ) = ( x e. RR , y e. RR |-> { <. 1 , x >. , <. 2 , y >. } ) | 
						
							| 8 | 1 2 7 4 | rrx2plordisom |  |-  ( x e. RR , y e. RR |-> { <. 1 , x >. , <. 2 , y >. } ) Isom { <. x , y >. | ( ( x e. ( RR X. RR ) /\ y e. ( RR X. RR ) ) /\ ( ( 1st ` x ) < ( 1st ` y ) \/ ( ( 1st ` x ) = ( 1st ` y ) /\ ( 2nd ` x ) < ( 2nd ` y ) ) ) ) } , O ( ( RR X. RR ) , R ) | 
						
							| 9 |  | isoso |  |-  ( ( x e. RR , y e. RR |-> { <. 1 , x >. , <. 2 , y >. } ) Isom { <. x , y >. | ( ( x e. ( RR X. RR ) /\ y e. ( RR X. RR ) ) /\ ( ( 1st ` x ) < ( 1st ` y ) \/ ( ( 1st ` x ) = ( 1st ` y ) /\ ( 2nd ` x ) < ( 2nd ` y ) ) ) ) } , O ( ( RR X. RR ) , R ) -> ( { <. x , y >. | ( ( x e. ( RR X. RR ) /\ y e. ( RR X. RR ) ) /\ ( ( 1st ` x ) < ( 1st ` y ) \/ ( ( 1st ` x ) = ( 1st ` y ) /\ ( 2nd ` x ) < ( 2nd ` y ) ) ) ) } Or ( RR X. RR ) <-> O Or R ) ) | 
						
							| 10 | 8 9 | ax-mp |  |-  ( { <. x , y >. | ( ( x e. ( RR X. RR ) /\ y e. ( RR X. RR ) ) /\ ( ( 1st ` x ) < ( 1st ` y ) \/ ( ( 1st ` x ) = ( 1st ` y ) /\ ( 2nd ` x ) < ( 2nd ` y ) ) ) ) } Or ( RR X. RR ) <-> O Or R ) | 
						
							| 11 | 6 10 | mpbi |  |-  O Or R |