| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fvex |  |-  ( f ` a ) e. _V | 
						
							| 2 |  | fvex |  |-  ( f ` suc a ) e. _V | 
						
							| 3 | 2 | brresi |  |-  ( ( f ` a ) ( R |` _V ) ( f ` suc a ) <-> ( ( f ` a ) e. _V /\ ( f ` a ) R ( f ` suc a ) ) ) | 
						
							| 4 | 1 3 | mpbiran |  |-  ( ( f ` a ) ( R |` _V ) ( f ` suc a ) <-> ( f ` a ) R ( f ` suc a ) ) | 
						
							| 5 | 4 | ralbii |  |-  ( A. a e. n ( f ` a ) ( R |` _V ) ( f ` suc a ) <-> A. a e. n ( f ` a ) R ( f ` suc a ) ) | 
						
							| 6 | 5 | 3anbi3i |  |-  ( ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) ( R |` _V ) ( f ` suc a ) ) <-> ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) R ( f ` suc a ) ) ) | 
						
							| 7 | 6 | exbii |  |-  ( E. f ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) ( R |` _V ) ( f ` suc a ) ) <-> E. f ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) R ( f ` suc a ) ) ) | 
						
							| 8 | 7 | rexbii |  |-  ( E. n e. ( _om \ 1o ) E. f ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) ( R |` _V ) ( f ` suc a ) ) <-> E. n e. ( _om \ 1o ) E. f ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) R ( f ` suc a ) ) ) | 
						
							| 9 | 8 | opabbii |  |-  { <. x , y >. | E. n e. ( _om \ 1o ) E. f ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) ( R |` _V ) ( f ` suc a ) ) } = { <. x , y >. | E. n e. ( _om \ 1o ) E. f ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) R ( f ` suc a ) ) } | 
						
							| 10 |  | df-ttrcl |  |-  t++ ( R |` _V ) = { <. x , y >. | E. n e. ( _om \ 1o ) E. f ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) ( R |` _V ) ( f ` suc a ) ) } | 
						
							| 11 |  | df-ttrcl |  |-  t++ R = { <. x , y >. | E. n e. ( _om \ 1o ) E. f ( f Fn suc n /\ ( ( f ` (/) ) = x /\ ( f ` n ) = y ) /\ A. a e. n ( f ` a ) R ( f ` suc a ) ) } | 
						
							| 12 | 9 10 11 | 3eqtr4i |  |-  t++ ( R |` _V ) = t++ R |