| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elovmporab1.o |  |-  O = ( x e. _V , y e. _V |-> { z e. [_ x / m ]_ M | ph } ) | 
						
							| 2 |  | elovmporab1.v |  |-  ( ( X e. _V /\ Y e. _V ) -> [_ X / m ]_ M e. _V ) | 
						
							| 3 | 1 | elmpocl |  |-  ( Z e. ( X O Y ) -> ( X e. _V /\ Y e. _V ) ) | 
						
							| 4 | 1 | a1i |  |-  ( ( X e. _V /\ Y e. _V ) -> O = ( x e. _V , y e. _V |-> { z e. [_ x / m ]_ M | ph } ) ) | 
						
							| 5 |  | csbeq1 |  |-  ( x = X -> [_ x / m ]_ M = [_ X / m ]_ M ) | 
						
							| 6 | 5 | ad2antrl |  |-  ( ( ( X e. _V /\ Y e. _V ) /\ ( x = X /\ y = Y ) ) -> [_ x / m ]_ M = [_ X / m ]_ M ) | 
						
							| 7 |  | sbceq1a |  |-  ( y = Y -> ( ph <-> [. Y / y ]. ph ) ) | 
						
							| 8 |  | sbceq1a |  |-  ( x = X -> ( [. Y / y ]. ph <-> [. X / x ]. [. Y / y ]. ph ) ) | 
						
							| 9 | 7 8 | sylan9bbr |  |-  ( ( x = X /\ y = Y ) -> ( ph <-> [. X / x ]. [. Y / y ]. ph ) ) | 
						
							| 10 | 9 | adantl |  |-  ( ( ( X e. _V /\ Y e. _V ) /\ ( x = X /\ y = Y ) ) -> ( ph <-> [. X / x ]. [. Y / y ]. ph ) ) | 
						
							| 11 | 6 10 | rabeqbidv |  |-  ( ( ( X e. _V /\ Y e. _V ) /\ ( x = X /\ y = Y ) ) -> { z e. [_ x / m ]_ M | ph } = { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } ) | 
						
							| 12 |  | eqidd |  |-  ( ( ( X e. _V /\ Y e. _V ) /\ x = X ) -> _V = _V ) | 
						
							| 13 |  | simpl |  |-  ( ( X e. _V /\ Y e. _V ) -> X e. _V ) | 
						
							| 14 |  | simpr |  |-  ( ( X e. _V /\ Y e. _V ) -> Y e. _V ) | 
						
							| 15 |  | rabexg |  |-  ( [_ X / m ]_ M e. _V -> { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } e. _V ) | 
						
							| 16 | 2 15 | syl |  |-  ( ( X e. _V /\ Y e. _V ) -> { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } e. _V ) | 
						
							| 17 |  | nfcv |  |-  F/_ x X | 
						
							| 18 | 17 | nfel1 |  |-  F/ x X e. _V | 
						
							| 19 |  | nfcv |  |-  F/_ x Y | 
						
							| 20 | 19 | nfel1 |  |-  F/ x Y e. _V | 
						
							| 21 | 18 20 | nfan |  |-  F/ x ( X e. _V /\ Y e. _V ) | 
						
							| 22 |  | nfcv |  |-  F/_ y X | 
						
							| 23 | 22 | nfel1 |  |-  F/ y X e. _V | 
						
							| 24 |  | nfcv |  |-  F/_ y Y | 
						
							| 25 | 24 | nfel1 |  |-  F/ y Y e. _V | 
						
							| 26 | 23 25 | nfan |  |-  F/ y ( X e. _V /\ Y e. _V ) | 
						
							| 27 |  | nfsbc1v |  |-  F/ x [. X / x ]. [. Y / y ]. ph | 
						
							| 28 |  | nfcv |  |-  F/_ x M | 
						
							| 29 | 17 28 | nfcsb |  |-  F/_ x [_ X / m ]_ M | 
						
							| 30 | 27 29 | nfrab |  |-  F/_ x { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } | 
						
							| 31 |  | nfsbc1v |  |-  F/ y [. Y / y ]. ph | 
						
							| 32 | 22 31 | nfsbc |  |-  F/ y [. X / x ]. [. Y / y ]. ph | 
						
							| 33 |  | nfcv |  |-  F/_ y M | 
						
							| 34 | 22 33 | nfcsb |  |-  F/_ y [_ X / m ]_ M | 
						
							| 35 | 32 34 | nfrab |  |-  F/_ y { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } | 
						
							| 36 | 4 11 12 13 14 16 21 26 22 19 30 35 | ovmpodxf |  |-  ( ( X e. _V /\ Y e. _V ) -> ( X O Y ) = { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } ) | 
						
							| 37 | 36 | eleq2d |  |-  ( ( X e. _V /\ Y e. _V ) -> ( Z e. ( X O Y ) <-> Z e. { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } ) ) | 
						
							| 38 |  | df-3an |  |-  ( ( X e. _V /\ Y e. _V /\ Z e. [_ X / m ]_ M ) <-> ( ( X e. _V /\ Y e. _V ) /\ Z e. [_ X / m ]_ M ) ) | 
						
							| 39 | 38 | simplbi2com |  |-  ( Z e. [_ X / m ]_ M -> ( ( X e. _V /\ Y e. _V ) -> ( X e. _V /\ Y e. _V /\ Z e. [_ X / m ]_ M ) ) ) | 
						
							| 40 |  | elrabi |  |-  ( Z e. { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } -> Z e. [_ X / m ]_ M ) | 
						
							| 41 | 39 40 | syl11 |  |-  ( ( X e. _V /\ Y e. _V ) -> ( Z e. { z e. [_ X / m ]_ M | [. X / x ]. [. Y / y ]. ph } -> ( X e. _V /\ Y e. _V /\ Z e. [_ X / m ]_ M ) ) ) | 
						
							| 42 | 37 41 | sylbid |  |-  ( ( X e. _V /\ Y e. _V ) -> ( Z e. ( X O Y ) -> ( X e. _V /\ Y e. _V /\ Z e. [_ X / m ]_ M ) ) ) | 
						
							| 43 | 3 42 | mpcom |  |-  ( Z e. ( X O Y ) -> ( X e. _V /\ Y e. _V /\ Z e. [_ X / m ]_ M ) ) |