| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							pj1eu.a | 
							⊢  +   =  ( +g ‘ 𝐺 )  | 
						
						
							| 2 | 
							
								
							 | 
							pj1eu.s | 
							⊢  ⊕   =  ( LSSum ‘ 𝐺 )  | 
						
						
							| 3 | 
							
								
							 | 
							pj1eu.o | 
							⊢  0   =  ( 0g ‘ 𝐺 )  | 
						
						
							| 4 | 
							
								
							 | 
							pj1eu.z | 
							⊢ 𝑍  =  ( Cntz ‘ 𝐺 )  | 
						
						
							| 5 | 
							
								
							 | 
							pj1eu.2 | 
							⊢ ( 𝜑  →  𝑇  ∈  ( SubGrp ‘ 𝐺 ) )  | 
						
						
							| 6 | 
							
								
							 | 
							pj1eu.3 | 
							⊢ ( 𝜑  →  𝑈  ∈  ( SubGrp ‘ 𝐺 ) )  | 
						
						
							| 7 | 
							
								
							 | 
							pj1eu.4 | 
							⊢ ( 𝜑  →  ( 𝑇  ∩  𝑈 )  =  {  0  } )  | 
						
						
							| 8 | 
							
								
							 | 
							pj1eu.5 | 
							⊢ ( 𝜑  →  𝑇  ⊆  ( 𝑍 ‘ 𝑈 ) )  | 
						
						
							| 9 | 
							
								
							 | 
							pj1f.p | 
							⊢ 𝑃  =  ( proj1 ‘ 𝐺 )  | 
						
						
							| 10 | 
							
								
							 | 
							subgrcl | 
							⊢ ( 𝑇  ∈  ( SubGrp ‘ 𝐺 )  →  𝐺  ∈  Grp )  | 
						
						
							| 11 | 
							
								5 10
							 | 
							syl | 
							⊢ ( 𝜑  →  𝐺  ∈  Grp )  | 
						
						
							| 12 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝐺 )  =  ( Base ‘ 𝐺 )  | 
						
						
							| 13 | 
							
								12
							 | 
							subgss | 
							⊢ ( 𝑇  ∈  ( SubGrp ‘ 𝐺 )  →  𝑇  ⊆  ( Base ‘ 𝐺 ) )  | 
						
						
							| 14 | 
							
								5 13
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑇  ⊆  ( Base ‘ 𝐺 ) )  | 
						
						
							| 15 | 
							
								12
							 | 
							subgss | 
							⊢ ( 𝑈  ∈  ( SubGrp ‘ 𝐺 )  →  𝑈  ⊆  ( Base ‘ 𝐺 ) )  | 
						
						
							| 16 | 
							
								6 15
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑈  ⊆  ( Base ‘ 𝐺 ) )  | 
						
						
							| 17 | 
							
								11 14 16
							 | 
							3jca | 
							⊢ ( 𝜑  →  ( 𝐺  ∈  Grp  ∧  𝑇  ⊆  ( Base ‘ 𝐺 )  ∧  𝑈  ⊆  ( Base ‘ 𝐺 ) ) )  | 
						
						
							| 18 | 
							
								12 1 2 9
							 | 
							pj1val | 
							⊢ ( ( ( 𝐺  ∈  Grp  ∧  𝑇  ⊆  ( Base ‘ 𝐺 )  ∧  𝑈  ⊆  ( Base ‘ 𝐺 ) )  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  →  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  =  ( ℩ 𝑥  ∈  𝑇 ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) ) )  | 
						
						
							| 19 | 
							
								17 18
							 | 
							sylan | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  →  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  =  ( ℩ 𝑥  ∈  𝑇 ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) ) )  | 
						
						
							| 20 | 
							
								1 2 3 4 5 6 7 8
							 | 
							pj1eu | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  →  ∃! 𝑥  ∈  𝑇 ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) )  | 
						
						
							| 21 | 
							
								
							 | 
							riotacl2 | 
							⊢ ( ∃! 𝑥  ∈  𝑇 ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 )  →  ( ℩ 𝑥  ∈  𝑇 ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) )  ∈  { 𝑥  ∈  𝑇  ∣  ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) } )  | 
						
						
							| 22 | 
							
								20 21
							 | 
							syl | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  →  ( ℩ 𝑥  ∈  𝑇 ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) )  ∈  { 𝑥  ∈  𝑇  ∣  ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) } )  | 
						
						
							| 23 | 
							
								19 22
							 | 
							eqeltrd | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  →  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  ∈  { 𝑥  ∈  𝑇  ∣  ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) } )  | 
						
						
							| 24 | 
							
								
							 | 
							oveq1 | 
							⊢ ( 𝑥  =  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  →  ( 𝑥  +  𝑦 )  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) )  | 
						
						
							| 25 | 
							
								24
							 | 
							eqeq2d | 
							⊢ ( 𝑥  =  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  →  ( 𝑋  =  ( 𝑥  +  𝑦 )  ↔  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  | 
						
						
							| 26 | 
							
								25
							 | 
							rexbidv | 
							⊢ ( 𝑥  =  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  →  ( ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 )  ↔  ∃ 𝑦  ∈  𝑈 𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  | 
						
						
							| 27 | 
							
								26
							 | 
							elrab | 
							⊢ ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  ∈  { 𝑥  ∈  𝑇  ∣  ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) }  ↔  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  ∈  𝑇  ∧  ∃ 𝑦  ∈  𝑈 𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  | 
						
						
							| 28 | 
							
								27
							 | 
							simprbi | 
							⊢ ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  ∈  { 𝑥  ∈  𝑇  ∣  ∃ 𝑦  ∈  𝑈 𝑋  =  ( 𝑥  +  𝑦 ) }  →  ∃ 𝑦  ∈  𝑈 𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) )  | 
						
						
							| 29 | 
							
								23 28
							 | 
							syl | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  →  ∃ 𝑦  ∈  𝑈 𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) )  | 
						
						
							| 30 | 
							
								
							 | 
							simprr | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) )  | 
						
						
							| 31 | 
							
								11
							 | 
							ad2antrr | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝐺  ∈  Grp )  | 
						
						
							| 32 | 
							
								16
							 | 
							ad2antrr | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑈  ⊆  ( Base ‘ 𝐺 ) )  | 
						
						
							| 33 | 
							
								14
							 | 
							ad2antrr | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑇  ⊆  ( Base ‘ 𝐺 ) )  | 
						
						
							| 34 | 
							
								
							 | 
							simplr | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  | 
						
						
							| 35 | 
							
								2 4
							 | 
							lsmcom2 | 
							⊢ ( ( 𝑇  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑈  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑇  ⊆  ( 𝑍 ‘ 𝑈 ) )  →  ( 𝑇  ⊕  𝑈 )  =  ( 𝑈  ⊕  𝑇 ) )  | 
						
						
							| 36 | 
							
								5 6 8 35
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( 𝑇  ⊕  𝑈 )  =  ( 𝑈  ⊕  𝑇 ) )  | 
						
						
							| 37 | 
							
								36
							 | 
							ad2antrr | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( 𝑇  ⊕  𝑈 )  =  ( 𝑈  ⊕  𝑇 ) )  | 
						
						
							| 38 | 
							
								34 37
							 | 
							eleqtrd | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑋  ∈  ( 𝑈  ⊕  𝑇 ) )  | 
						
						
							| 39 | 
							
								12 1 2 9
							 | 
							pj1val | 
							⊢ ( ( ( 𝐺  ∈  Grp  ∧  𝑈  ⊆  ( Base ‘ 𝐺 )  ∧  𝑇  ⊆  ( Base ‘ 𝐺 ) )  ∧  𝑋  ∈  ( 𝑈  ⊕  𝑇 ) )  →  ( ( 𝑈 𝑃 𝑇 ) ‘ 𝑋 )  =  ( ℩ 𝑢  ∈  𝑈 ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 ) ) )  | 
						
						
							| 40 | 
							
								31 32 33 38 39
							 | 
							syl31anc | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( ( 𝑈 𝑃 𝑇 ) ‘ 𝑋 )  =  ( ℩ 𝑢  ∈  𝑈 ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 ) ) )  | 
						
						
							| 41 | 
							
								1 2 3 4 5 6 7 8 9
							 | 
							pj1f | 
							⊢ ( 𝜑  →  ( 𝑇 𝑃 𝑈 ) : ( 𝑇  ⊕  𝑈 ) ⟶ 𝑇 )  | 
						
						
							| 42 | 
							
								41
							 | 
							ad2antrr | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( 𝑇 𝑃 𝑈 ) : ( 𝑇  ⊕  𝑈 ) ⟶ 𝑇 )  | 
						
						
							| 43 | 
							
								42 34
							 | 
							ffvelcdmd | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  ∈  𝑇 )  | 
						
						
							| 44 | 
							
								8
							 | 
							ad2antrr | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑇  ⊆  ( 𝑍 ‘ 𝑈 ) )  | 
						
						
							| 45 | 
							
								44 43
							 | 
							sseldd | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  ∈  ( 𝑍 ‘ 𝑈 ) )  | 
						
						
							| 46 | 
							
								
							 | 
							simprl | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑦  ∈  𝑈 )  | 
						
						
							| 47 | 
							
								1 4
							 | 
							cntzi | 
							⊢ ( ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  ∈  ( 𝑍 ‘ 𝑈 )  ∧  𝑦  ∈  𝑈 )  →  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 )  =  ( 𝑦  +  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 ) ) )  | 
						
						
							| 48 | 
							
								45 46 47
							 | 
							syl2anc | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 )  =  ( 𝑦  +  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 ) ) )  | 
						
						
							| 49 | 
							
								30 48
							 | 
							eqtrd | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑋  =  ( 𝑦  +  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 ) ) )  | 
						
						
							| 50 | 
							
								
							 | 
							oveq2 | 
							⊢ ( 𝑣  =  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  →  ( 𝑦  +  𝑣 )  =  ( 𝑦  +  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 ) ) )  | 
						
						
							| 51 | 
							
								50
							 | 
							rspceeqv | 
							⊢ ( ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  ∈  𝑇  ∧  𝑋  =  ( 𝑦  +  ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 ) ) )  →  ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑦  +  𝑣 ) )  | 
						
						
							| 52 | 
							
								43 49 51
							 | 
							syl2anc | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑦  +  𝑣 ) )  | 
						
						
							| 53 | 
							
								
							 | 
							simpll | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝜑 )  | 
						
						
							| 54 | 
							
								
							 | 
							incom | 
							⊢ ( 𝑈  ∩  𝑇 )  =  ( 𝑇  ∩  𝑈 )  | 
						
						
							| 55 | 
							
								54 7
							 | 
							eqtrid | 
							⊢ ( 𝜑  →  ( 𝑈  ∩  𝑇 )  =  {  0  } )  | 
						
						
							| 56 | 
							
								4 5 6 8
							 | 
							cntzrecd | 
							⊢ ( 𝜑  →  𝑈  ⊆  ( 𝑍 ‘ 𝑇 ) )  | 
						
						
							| 57 | 
							
								1 2 3 4 6 5 55 56
							 | 
							pj1eu | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  ( 𝑈  ⊕  𝑇 ) )  →  ∃! 𝑢  ∈  𝑈 ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 ) )  | 
						
						
							| 58 | 
							
								53 38 57
							 | 
							syl2anc | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ∃! 𝑢  ∈  𝑈 ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 ) )  | 
						
						
							| 59 | 
							
								
							 | 
							oveq1 | 
							⊢ ( 𝑢  =  𝑦  →  ( 𝑢  +  𝑣 )  =  ( 𝑦  +  𝑣 ) )  | 
						
						
							| 60 | 
							
								59
							 | 
							eqeq2d | 
							⊢ ( 𝑢  =  𝑦  →  ( 𝑋  =  ( 𝑢  +  𝑣 )  ↔  𝑋  =  ( 𝑦  +  𝑣 ) ) )  | 
						
						
							| 61 | 
							
								60
							 | 
							rexbidv | 
							⊢ ( 𝑢  =  𝑦  →  ( ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 )  ↔  ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑦  +  𝑣 ) ) )  | 
						
						
							| 62 | 
							
								61
							 | 
							riota2 | 
							⊢ ( ( 𝑦  ∈  𝑈  ∧  ∃! 𝑢  ∈  𝑈 ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 ) )  →  ( ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑦  +  𝑣 )  ↔  ( ℩ 𝑢  ∈  𝑈 ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 ) )  =  𝑦 ) )  | 
						
						
							| 63 | 
							
								46 58 62
							 | 
							syl2anc | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑦  +  𝑣 )  ↔  ( ℩ 𝑢  ∈  𝑈 ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 ) )  =  𝑦 ) )  | 
						
						
							| 64 | 
							
								52 63
							 | 
							mpbid | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( ℩ 𝑢  ∈  𝑈 ∃ 𝑣  ∈  𝑇 𝑋  =  ( 𝑢  +  𝑣 ) )  =  𝑦 )  | 
						
						
							| 65 | 
							
								40 64
							 | 
							eqtrd | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( ( 𝑈 𝑃 𝑇 ) ‘ 𝑋 )  =  𝑦 )  | 
						
						
							| 66 | 
							
								65
							 | 
							oveq2d | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  ( ( 𝑈 𝑃 𝑇 ) ‘ 𝑋 ) )  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) )  | 
						
						
							| 67 | 
							
								30 66
							 | 
							eqtr4d | 
							⊢ ( ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  ∧  ( 𝑦  ∈  𝑈  ∧  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  𝑦 ) ) )  →  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  ( ( 𝑈 𝑃 𝑇 ) ‘ 𝑋 ) ) )  | 
						
						
							| 68 | 
							
								29 67
							 | 
							rexlimddv | 
							⊢ ( ( 𝜑  ∧  𝑋  ∈  ( 𝑇  ⊕  𝑈 ) )  →  𝑋  =  ( ( ( 𝑇 𝑃 𝑈 ) ‘ 𝑋 )  +  ( ( 𝑈 𝑃 𝑇 ) ‘ 𝑋 ) ) )  |