| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sategoelfvb.s |  |-  E = ( M SatE ( A e.g B ) ) | 
						
							| 2 |  | ex-sategoelel.s |  |-  S = ( x e. _om |-> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) ) | 
						
							| 3 |  | simpr |  |-  ( ( M e. WUni /\ Z e. M ) -> Z e. M ) | 
						
							| 4 |  | simpl |  |-  ( ( M e. WUni /\ Z e. M ) -> M e. WUni ) | 
						
							| 5 | 4 3 | wunpw |  |-  ( ( M e. WUni /\ Z e. M ) -> ~P Z e. M ) | 
						
							| 6 | 4 | wun0 |  |-  ( ( M e. WUni /\ Z e. M ) -> (/) e. M ) | 
						
							| 7 | 5 6 | ifcld |  |-  ( ( M e. WUni /\ Z e. M ) -> if ( x = B , ~P Z , (/) ) e. M ) | 
						
							| 8 | 3 7 | ifcld |  |-  ( ( M e. WUni /\ Z e. M ) -> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) e. M ) | 
						
							| 9 | 8 | adantr |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) e. M ) | 
						
							| 10 | 9 | adantr |  |-  ( ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) /\ x e. _om ) -> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) e. M ) | 
						
							| 11 | 10 2 | fmptd |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> S : _om --> M ) | 
						
							| 12 | 4 | adantr |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> M e. WUni ) | 
						
							| 13 |  | omex |  |-  _om e. _V | 
						
							| 14 | 13 | a1i |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> _om e. _V ) | 
						
							| 15 | 12 14 | elmapd |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> ( S e. ( M ^m _om ) <-> S : _om --> M ) ) | 
						
							| 16 | 11 15 | mpbird |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> S e. ( M ^m _om ) ) | 
						
							| 17 |  | pwidg |  |-  ( Z e. M -> Z e. ~P Z ) | 
						
							| 18 | 17 | adantl |  |-  ( ( M e. WUni /\ Z e. M ) -> Z e. ~P Z ) | 
						
							| 19 | 18 | adantr |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> Z e. ~P Z ) | 
						
							| 20 | 2 | a1i |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> S = ( x e. _om |-> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) ) ) | 
						
							| 21 |  | iftrue |  |-  ( x = A -> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) = Z ) | 
						
							| 22 | 21 | adantl |  |-  ( ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) /\ x = A ) -> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) = Z ) | 
						
							| 23 |  | simpr1 |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> A e. _om ) | 
						
							| 24 | 3 | adantr |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> Z e. M ) | 
						
							| 25 | 20 22 23 24 | fvmptd |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> ( S ` A ) = Z ) | 
						
							| 26 |  | eqeq1 |  |-  ( x = B -> ( x = A <-> B = A ) ) | 
						
							| 27 |  | eqeq1 |  |-  ( x = B -> ( x = B <-> B = B ) ) | 
						
							| 28 | 27 | ifbid |  |-  ( x = B -> if ( x = B , ~P Z , (/) ) = if ( B = B , ~P Z , (/) ) ) | 
						
							| 29 | 26 28 | ifbieq2d |  |-  ( x = B -> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) = if ( B = A , Z , if ( B = B , ~P Z , (/) ) ) ) | 
						
							| 30 |  | necom |  |-  ( A =/= B <-> B =/= A ) | 
						
							| 31 |  | ifnefalse |  |-  ( B =/= A -> if ( B = A , Z , if ( B = B , ~P Z , (/) ) ) = if ( B = B , ~P Z , (/) ) ) | 
						
							| 32 | 30 31 | sylbi |  |-  ( A =/= B -> if ( B = A , Z , if ( B = B , ~P Z , (/) ) ) = if ( B = B , ~P Z , (/) ) ) | 
						
							| 33 | 32 | 3ad2ant3 |  |-  ( ( A e. _om /\ B e. _om /\ A =/= B ) -> if ( B = A , Z , if ( B = B , ~P Z , (/) ) ) = if ( B = B , ~P Z , (/) ) ) | 
						
							| 34 | 33 | adantl |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> if ( B = A , Z , if ( B = B , ~P Z , (/) ) ) = if ( B = B , ~P Z , (/) ) ) | 
						
							| 35 | 29 34 | sylan9eqr |  |-  ( ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) /\ x = B ) -> if ( x = A , Z , if ( x = B , ~P Z , (/) ) ) = if ( B = B , ~P Z , (/) ) ) | 
						
							| 36 |  | simpr2 |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> B e. _om ) | 
						
							| 37 |  | pwexg |  |-  ( Z e. M -> ~P Z e. _V ) | 
						
							| 38 | 37 | adantl |  |-  ( ( M e. WUni /\ Z e. M ) -> ~P Z e. _V ) | 
						
							| 39 |  | 0ex |  |-  (/) e. _V | 
						
							| 40 | 39 | a1i |  |-  ( ( M e. WUni /\ Z e. M ) -> (/) e. _V ) | 
						
							| 41 | 38 40 | ifcld |  |-  ( ( M e. WUni /\ Z e. M ) -> if ( B = B , ~P Z , (/) ) e. _V ) | 
						
							| 42 | 41 | adantr |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> if ( B = B , ~P Z , (/) ) e. _V ) | 
						
							| 43 | 20 35 36 42 | fvmptd |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> ( S ` B ) = if ( B = B , ~P Z , (/) ) ) | 
						
							| 44 |  | eqid |  |-  B = B | 
						
							| 45 | 44 | iftruei |  |-  if ( B = B , ~P Z , (/) ) = ~P Z | 
						
							| 46 | 43 45 | eqtrdi |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> ( S ` B ) = ~P Z ) | 
						
							| 47 | 19 25 46 | 3eltr4d |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> ( S ` A ) e. ( S ` B ) ) | 
						
							| 48 |  | 3simpa |  |-  ( ( A e. _om /\ B e. _om /\ A =/= B ) -> ( A e. _om /\ B e. _om ) ) | 
						
							| 49 | 1 | sategoelfvb |  |-  ( ( M e. WUni /\ ( A e. _om /\ B e. _om ) ) -> ( S e. E <-> ( S e. ( M ^m _om ) /\ ( S ` A ) e. ( S ` B ) ) ) ) | 
						
							| 50 | 4 48 49 | syl2an |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> ( S e. E <-> ( S e. ( M ^m _om ) /\ ( S ` A ) e. ( S ` B ) ) ) ) | 
						
							| 51 | 16 47 50 | mpbir2and |  |-  ( ( ( M e. WUni /\ Z e. M ) /\ ( A e. _om /\ B e. _om /\ A =/= B ) ) -> S e. E ) |