| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mclsval.d |  |-  D = ( mDV ` T ) | 
						
							| 2 |  | mclsval.e |  |-  E = ( mEx ` T ) | 
						
							| 3 |  | mclsval.c |  |-  C = ( mCls ` T ) | 
						
							| 4 |  | n0i |  |-  ( A e. ( K C B ) -> -. ( K C B ) = (/) ) | 
						
							| 5 |  | fvprc |  |-  ( -. T e. _V -> ( mCls ` T ) = (/) ) | 
						
							| 6 | 3 5 | eqtrid |  |-  ( -. T e. _V -> C = (/) ) | 
						
							| 7 | 6 | oveqd |  |-  ( -. T e. _V -> ( K C B ) = ( K (/) B ) ) | 
						
							| 8 |  | 0ov |  |-  ( K (/) B ) = (/) | 
						
							| 9 | 7 8 | eqtrdi |  |-  ( -. T e. _V -> ( K C B ) = (/) ) | 
						
							| 10 | 4 9 | nsyl2 |  |-  ( A e. ( K C B ) -> T e. _V ) | 
						
							| 11 |  | fveq2 |  |-  ( t = T -> ( mCls ` t ) = ( mCls ` T ) ) | 
						
							| 12 | 11 3 | eqtr4di |  |-  ( t = T -> ( mCls ` t ) = C ) | 
						
							| 13 | 12 | oveqd |  |-  ( t = T -> ( K ( mCls ` t ) B ) = ( K C B ) ) | 
						
							| 14 | 13 | eleq2d |  |-  ( t = T -> ( A e. ( K ( mCls ` t ) B ) <-> A e. ( K C B ) ) ) | 
						
							| 15 |  | fvex |  |-  ( mDV ` t ) e. _V | 
						
							| 16 | 15 | elpw2 |  |-  ( K e. ~P ( mDV ` t ) <-> K C_ ( mDV ` t ) ) | 
						
							| 17 |  | fveq2 |  |-  ( t = T -> ( mDV ` t ) = ( mDV ` T ) ) | 
						
							| 18 | 17 1 | eqtr4di |  |-  ( t = T -> ( mDV ` t ) = D ) | 
						
							| 19 | 18 | sseq2d |  |-  ( t = T -> ( K C_ ( mDV ` t ) <-> K C_ D ) ) | 
						
							| 20 | 16 19 | bitrid |  |-  ( t = T -> ( K e. ~P ( mDV ` t ) <-> K C_ D ) ) | 
						
							| 21 |  | fvex |  |-  ( mEx ` t ) e. _V | 
						
							| 22 | 21 | elpw2 |  |-  ( B e. ~P ( mEx ` t ) <-> B C_ ( mEx ` t ) ) | 
						
							| 23 |  | fveq2 |  |-  ( t = T -> ( mEx ` t ) = ( mEx ` T ) ) | 
						
							| 24 | 23 2 | eqtr4di |  |-  ( t = T -> ( mEx ` t ) = E ) | 
						
							| 25 | 24 | sseq2d |  |-  ( t = T -> ( B C_ ( mEx ` t ) <-> B C_ E ) ) | 
						
							| 26 | 22 25 | bitrid |  |-  ( t = T -> ( B e. ~P ( mEx ` t ) <-> B C_ E ) ) | 
						
							| 27 | 20 26 | anbi12d |  |-  ( t = T -> ( ( K e. ~P ( mDV ` t ) /\ B e. ~P ( mEx ` t ) ) <-> ( K C_ D /\ B C_ E ) ) ) | 
						
							| 28 | 14 27 | imbi12d |  |-  ( t = T -> ( ( A e. ( K ( mCls ` t ) B ) -> ( K e. ~P ( mDV ` t ) /\ B e. ~P ( mEx ` t ) ) ) <-> ( A e. ( K C B ) -> ( K C_ D /\ B C_ E ) ) ) ) | 
						
							| 29 |  | vex |  |-  t e. _V | 
						
							| 30 | 15 | pwex |  |-  ~P ( mDV ` t ) e. _V | 
						
							| 31 | 21 | pwex |  |-  ~P ( mEx ` t ) e. _V | 
						
							| 32 | 30 31 | mpoex |  |-  ( d e. ~P ( mDV ` t ) , h e. ~P ( mEx ` t ) |-> |^| { c | ( ( h u. ran ( mVH ` t ) ) C_ c /\ A. m A. o A. p ( <. m , o , p >. e. ( mAx ` t ) -> A. s e. ran ( mSubst ` t ) ( ( ( s " ( o u. ran ( mVH ` t ) ) ) C_ c /\ A. x A. y ( x m y -> ( ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` x ) ) ) X. ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` y ) ) ) ) C_ d ) ) -> ( s ` p ) e. c ) ) ) } ) e. _V | 
						
							| 33 |  | df-mcls |  |-  mCls = ( t e. _V |-> ( d e. ~P ( mDV ` t ) , h e. ~P ( mEx ` t ) |-> |^| { c | ( ( h u. ran ( mVH ` t ) ) C_ c /\ A. m A. o A. p ( <. m , o , p >. e. ( mAx ` t ) -> A. s e. ran ( mSubst ` t ) ( ( ( s " ( o u. ran ( mVH ` t ) ) ) C_ c /\ A. x A. y ( x m y -> ( ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` x ) ) ) X. ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` y ) ) ) ) C_ d ) ) -> ( s ` p ) e. c ) ) ) } ) ) | 
						
							| 34 | 33 | fvmpt2 |  |-  ( ( t e. _V /\ ( d e. ~P ( mDV ` t ) , h e. ~P ( mEx ` t ) |-> |^| { c | ( ( h u. ran ( mVH ` t ) ) C_ c /\ A. m A. o A. p ( <. m , o , p >. e. ( mAx ` t ) -> A. s e. ran ( mSubst ` t ) ( ( ( s " ( o u. ran ( mVH ` t ) ) ) C_ c /\ A. x A. y ( x m y -> ( ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` x ) ) ) X. ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` y ) ) ) ) C_ d ) ) -> ( s ` p ) e. c ) ) ) } ) e. _V ) -> ( mCls ` t ) = ( d e. ~P ( mDV ` t ) , h e. ~P ( mEx ` t ) |-> |^| { c | ( ( h u. ran ( mVH ` t ) ) C_ c /\ A. m A. o A. p ( <. m , o , p >. e. ( mAx ` t ) -> A. s e. ran ( mSubst ` t ) ( ( ( s " ( o u. ran ( mVH ` t ) ) ) C_ c /\ A. x A. y ( x m y -> ( ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` x ) ) ) X. ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` y ) ) ) ) C_ d ) ) -> ( s ` p ) e. c ) ) ) } ) ) | 
						
							| 35 | 29 32 34 | mp2an |  |-  ( mCls ` t ) = ( d e. ~P ( mDV ` t ) , h e. ~P ( mEx ` t ) |-> |^| { c | ( ( h u. ran ( mVH ` t ) ) C_ c /\ A. m A. o A. p ( <. m , o , p >. e. ( mAx ` t ) -> A. s e. ran ( mSubst ` t ) ( ( ( s " ( o u. ran ( mVH ` t ) ) ) C_ c /\ A. x A. y ( x m y -> ( ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` x ) ) ) X. ( ( mVars ` t ) ` ( s ` ( ( mVH ` t ) ` y ) ) ) ) C_ d ) ) -> ( s ` p ) e. c ) ) ) } ) | 
						
							| 36 | 35 | elmpocl |  |-  ( A e. ( K ( mCls ` t ) B ) -> ( K e. ~P ( mDV ` t ) /\ B e. ~P ( mEx ` t ) ) ) | 
						
							| 37 | 28 36 | vtoclg |  |-  ( T e. _V -> ( A e. ( K C B ) -> ( K C_ D /\ B C_ E ) ) ) | 
						
							| 38 | 10 37 | mpcom |  |-  ( A e. ( K C B ) -> ( K C_ D /\ B C_ E ) ) | 
						
							| 39 | 38 | simpld |  |-  ( A e. ( K C B ) -> K C_ D ) | 
						
							| 40 | 38 | simprd |  |-  ( A e. ( K C B ) -> B C_ E ) | 
						
							| 41 | 10 39 40 | 3jca |  |-  ( A e. ( K C B ) -> ( T e. _V /\ K C_ D /\ B C_ E ) ) |