| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							dprdcntz2.1 | 
							 |-  ( ph -> G dom DProd S )  | 
						
						
							| 2 | 
							
								
							 | 
							dprdcntz2.2 | 
							 |-  ( ph -> dom S = I )  | 
						
						
							| 3 | 
							
								
							 | 
							dprdcntz2.c | 
							 |-  ( ph -> C C_ I )  | 
						
						
							| 4 | 
							
								
							 | 
							dprdcntz2.d | 
							 |-  ( ph -> D C_ I )  | 
						
						
							| 5 | 
							
								
							 | 
							dprdcntz2.i | 
							 |-  ( ph -> ( C i^i D ) = (/) )  | 
						
						
							| 6 | 
							
								
							 | 
							dprddisj2.0 | 
							 |-  .0. = ( 0g ` G )  | 
						
						
							| 7 | 
							
								
							 | 
							inss1 | 
							 |-  ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) C_ ( G DProd ( S |` C ) )  | 
						
						
							| 8 | 
							
								1 2 3
							 | 
							dprdres | 
							 |-  ( ph -> ( G dom DProd ( S |` C ) /\ ( G DProd ( S |` C ) ) C_ ( G DProd S ) ) )  | 
						
						
							| 9 | 
							
								8
							 | 
							simprd | 
							 |-  ( ph -> ( G DProd ( S |` C ) ) C_ ( G DProd S ) )  | 
						
						
							| 10 | 
							
								7 9
							 | 
							sstrid | 
							 |-  ( ph -> ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) C_ ( G DProd S ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							sseld | 
							 |-  ( ph -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) -> x e. ( G DProd S ) ) )  | 
						
						
							| 12 | 
							
								
							 | 
							eqid | 
							 |-  { h e. X_ i e. I ( S ` i ) | h finSupp .0. } = { h e. X_ i e. I ( S ` i ) | h finSupp .0. } | 
						
						
							| 13 | 
							
								6 12
							 | 
							eldprd | 
							 |-  ( dom S = I -> ( x e. ( G DProd S ) <-> ( G dom DProd S /\ E. f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } x = ( G gsum f ) ) ) ) | 
						
						
							| 14 | 
							
								2 13
							 | 
							syl | 
							 |-  ( ph -> ( x e. ( G DProd S ) <-> ( G dom DProd S /\ E. f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } x = ( G gsum f ) ) ) ) | 
						
						
							| 15 | 
							
								1
							 | 
							ad2antrr | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> G dom DProd S ) | 
						
						
							| 16 | 
							
								2
							 | 
							ad2antrr | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> dom S = I ) | 
						
						
							| 17 | 
							
								
							 | 
							simplr | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) | 
						
						
							| 18 | 
							
								
							 | 
							eqid | 
							 |-  ( Base ` G ) = ( Base ` G )  | 
						
						
							| 19 | 
							
								12 15 16 17 18
							 | 
							dprdff | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> f : I --> ( Base ` G ) ) | 
						
						
							| 20 | 
							
								19
							 | 
							feqmptd | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> f = ( x e. I |-> ( f ` x ) ) ) | 
						
						
							| 21 | 
							
								5
							 | 
							difeq2d | 
							 |-  ( ph -> ( I \ ( C i^i D ) ) = ( I \ (/) ) )  | 
						
						
							| 22 | 
							
								
							 | 
							difindi | 
							 |-  ( I \ ( C i^i D ) ) = ( ( I \ C ) u. ( I \ D ) )  | 
						
						
							| 23 | 
							
								
							 | 
							dif0 | 
							 |-  ( I \ (/) ) = I  | 
						
						
							| 24 | 
							
								21 22 23
							 | 
							3eqtr3g | 
							 |-  ( ph -> ( ( I \ C ) u. ( I \ D ) ) = I )  | 
						
						
							| 25 | 
							
								
							 | 
							eqimss2 | 
							 |-  ( ( ( I \ C ) u. ( I \ D ) ) = I -> I C_ ( ( I \ C ) u. ( I \ D ) ) )  | 
						
						
							| 26 | 
							
								24 25
							 | 
							syl | 
							 |-  ( ph -> I C_ ( ( I \ C ) u. ( I \ D ) ) )  | 
						
						
							| 27 | 
							
								26
							 | 
							ad2antrr | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> I C_ ( ( I \ C ) u. ( I \ D ) ) ) | 
						
						
							| 28 | 
							
								27
							 | 
							sselda | 
							 |-  ( ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) /\ x e. I ) -> x e. ( ( I \ C ) u. ( I \ D ) ) ) | 
						
						
							| 29 | 
							
								
							 | 
							elun | 
							 |-  ( x e. ( ( I \ C ) u. ( I \ D ) ) <-> ( x e. ( I \ C ) \/ x e. ( I \ D ) ) )  | 
						
						
							| 30 | 
							
								28 29
							 | 
							sylib | 
							 |-  ( ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) /\ x e. I ) -> ( x e. ( I \ C ) \/ x e. ( I \ D ) ) ) | 
						
						
							| 31 | 
							
								3
							 | 
							ad2antrr | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> C C_ I ) | 
						
						
							| 32 | 
							
								
							 | 
							simprl | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> ( G gsum f ) e. ( G DProd ( S |` C ) ) ) | 
						
						
							| 33 | 
							
								6 12 15 16 31 17 32
							 | 
							dmdprdsplitlem | 
							 |-  ( ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) /\ x e. ( I \ C ) ) -> ( f ` x ) = .0. ) | 
						
						
							| 34 | 
							
								4
							 | 
							ad2antrr | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> D C_ I ) | 
						
						
							| 35 | 
							
								
							 | 
							simprr | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> ( G gsum f ) e. ( G DProd ( S |` D ) ) ) | 
						
						
							| 36 | 
							
								6 12 15 16 34 17 35
							 | 
							dmdprdsplitlem | 
							 |-  ( ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) /\ x e. ( I \ D ) ) -> ( f ` x ) = .0. ) | 
						
						
							| 37 | 
							
								33 36
							 | 
							jaodan | 
							 |-  ( ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) /\ ( x e. ( I \ C ) \/ x e. ( I \ D ) ) ) -> ( f ` x ) = .0. ) | 
						
						
							| 38 | 
							
								30 37
							 | 
							syldan | 
							 |-  ( ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) /\ x e. I ) -> ( f ` x ) = .0. ) | 
						
						
							| 39 | 
							
								38
							 | 
							mpteq2dva | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> ( x e. I |-> ( f ` x ) ) = ( x e. I |-> .0. ) ) | 
						
						
							| 40 | 
							
								20 39
							 | 
							eqtrd | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> f = ( x e. I |-> .0. ) ) | 
						
						
							| 41 | 
							
								40
							 | 
							oveq2d | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> ( G gsum f ) = ( G gsum ( x e. I |-> .0. ) ) ) | 
						
						
							| 42 | 
							
								
							 | 
							dprdgrp | 
							 |-  ( G dom DProd S -> G e. Grp )  | 
						
						
							| 43 | 
							
								
							 | 
							grpmnd | 
							 |-  ( G e. Grp -> G e. Mnd )  | 
						
						
							| 44 | 
							
								1 42 43
							 | 
							3syl | 
							 |-  ( ph -> G e. Mnd )  | 
						
						
							| 45 | 
							
								1 2
							 | 
							dprddomcld | 
							 |-  ( ph -> I e. _V )  | 
						
						
							| 46 | 
							
								6
							 | 
							gsumz | 
							 |-  ( ( G e. Mnd /\ I e. _V ) -> ( G gsum ( x e. I |-> .0. ) ) = .0. )  | 
						
						
							| 47 | 
							
								44 45 46
							 | 
							syl2anc | 
							 |-  ( ph -> ( G gsum ( x e. I |-> .0. ) ) = .0. )  | 
						
						
							| 48 | 
							
								47
							 | 
							ad2antrr | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> ( G gsum ( x e. I |-> .0. ) ) = .0. ) | 
						
						
							| 49 | 
							
								41 48
							 | 
							eqtrd | 
							 |-  ( ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) /\ ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) -> ( G gsum f ) = .0. ) | 
						
						
							| 50 | 
							
								49
							 | 
							ex | 
							 |-  ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) -> ( ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) -> ( G gsum f ) = .0. ) ) | 
						
						
							| 51 | 
							
								
							 | 
							eleq1 | 
							 |-  ( x = ( G gsum f ) -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) <-> ( G gsum f ) e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) ) )  | 
						
						
							| 52 | 
							
								
							 | 
							elin | 
							 |-  ( ( G gsum f ) e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) <-> ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) )  | 
						
						
							| 53 | 
							
								51 52
							 | 
							bitrdi | 
							 |-  ( x = ( G gsum f ) -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) <-> ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) ) )  | 
						
						
							| 54 | 
							
								
							 | 
							velsn | 
							 |-  ( x e. { .0. } <-> x = .0. ) | 
						
						
							| 55 | 
							
								
							 | 
							eqeq1 | 
							 |-  ( x = ( G gsum f ) -> ( x = .0. <-> ( G gsum f ) = .0. ) )  | 
						
						
							| 56 | 
							
								54 55
							 | 
							bitrid | 
							 |-  ( x = ( G gsum f ) -> ( x e. { .0. } <-> ( G gsum f ) = .0. ) ) | 
						
						
							| 57 | 
							
								53 56
							 | 
							imbi12d | 
							 |-  ( x = ( G gsum f ) -> ( ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) -> x e. { .0. } ) <-> ( ( ( G gsum f ) e. ( G DProd ( S |` C ) ) /\ ( G gsum f ) e. ( G DProd ( S |` D ) ) ) -> ( G gsum f ) = .0. ) ) ) | 
						
						
							| 58 | 
							
								50 57
							 | 
							syl5ibrcom | 
							 |-  ( ( ph /\ f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } ) -> ( x = ( G gsum f ) -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) -> x e. { .0. } ) ) ) | 
						
						
							| 59 | 
							
								58
							 | 
							rexlimdva | 
							 |-  ( ph -> ( E. f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } x = ( G gsum f ) -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) -> x e. { .0. } ) ) ) | 
						
						
							| 60 | 
							
								59
							 | 
							adantld | 
							 |-  ( ph -> ( ( G dom DProd S /\ E. f e. { h e. X_ i e. I ( S ` i ) | h finSupp .0. } x = ( G gsum f ) ) -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) -> x e. { .0. } ) ) ) | 
						
						
							| 61 | 
							
								14 60
							 | 
							sylbid | 
							 |-  ( ph -> ( x e. ( G DProd S ) -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) -> x e. { .0. } ) ) ) | 
						
						
							| 62 | 
							
								61
							 | 
							com23 | 
							 |-  ( ph -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) -> ( x e. ( G DProd S ) -> x e. { .0. } ) ) ) | 
						
						
							| 63 | 
							
								11 62
							 | 
							mpdd | 
							 |-  ( ph -> ( x e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) -> x e. { .0. } ) ) | 
						
						
							| 64 | 
							
								63
							 | 
							ssrdv | 
							 |-  ( ph -> ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) C_ { .0. } ) | 
						
						
							| 65 | 
							
								8
							 | 
							simpld | 
							 |-  ( ph -> G dom DProd ( S |` C ) )  | 
						
						
							| 66 | 
							
								
							 | 
							dprdsubg | 
							 |-  ( G dom DProd ( S |` C ) -> ( G DProd ( S |` C ) ) e. ( SubGrp ` G ) )  | 
						
						
							| 67 | 
							
								6
							 | 
							subg0cl | 
							 |-  ( ( G DProd ( S |` C ) ) e. ( SubGrp ` G ) -> .0. e. ( G DProd ( S |` C ) ) )  | 
						
						
							| 68 | 
							
								65 66 67
							 | 
							3syl | 
							 |-  ( ph -> .0. e. ( G DProd ( S |` C ) ) )  | 
						
						
							| 69 | 
							
								1 2 4
							 | 
							dprdres | 
							 |-  ( ph -> ( G dom DProd ( S |` D ) /\ ( G DProd ( S |` D ) ) C_ ( G DProd S ) ) )  | 
						
						
							| 70 | 
							
								69
							 | 
							simpld | 
							 |-  ( ph -> G dom DProd ( S |` D ) )  | 
						
						
							| 71 | 
							
								
							 | 
							dprdsubg | 
							 |-  ( G dom DProd ( S |` D ) -> ( G DProd ( S |` D ) ) e. ( SubGrp ` G ) )  | 
						
						
							| 72 | 
							
								6
							 | 
							subg0cl | 
							 |-  ( ( G DProd ( S |` D ) ) e. ( SubGrp ` G ) -> .0. e. ( G DProd ( S |` D ) ) )  | 
						
						
							| 73 | 
							
								70 71 72
							 | 
							3syl | 
							 |-  ( ph -> .0. e. ( G DProd ( S |` D ) ) )  | 
						
						
							| 74 | 
							
								68 73
							 | 
							elind | 
							 |-  ( ph -> .0. e. ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) )  | 
						
						
							| 75 | 
							
								74
							 | 
							snssd | 
							 |-  ( ph -> { .0. } C_ ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) ) | 
						
						
							| 76 | 
							
								64 75
							 | 
							eqssd | 
							 |-  ( ph -> ( ( G DProd ( S |` C ) ) i^i ( G DProd ( S |` D ) ) ) = { .0. } ) |