| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							dalem.ph | 
							⊢ ( 𝜑  ↔  ( ( ( 𝐾  ∈  HL  ∧  𝐶  ∈  ( Base ‘ 𝐾 ) )  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑅  ∈  𝐴 )  ∧  ( 𝑆  ∈  𝐴  ∧  𝑇  ∈  𝐴  ∧  𝑈  ∈  𝐴 ) )  ∧  ( 𝑌  ∈  𝑂  ∧  𝑍  ∈  𝑂 )  ∧  ( ( ¬  𝐶  ≤  ( 𝑃  ∨  𝑄 )  ∧  ¬  𝐶  ≤  ( 𝑄  ∨  𝑅 )  ∧  ¬  𝐶  ≤  ( 𝑅  ∨  𝑃 ) )  ∧  ( ¬  𝐶  ≤  ( 𝑆  ∨  𝑇 )  ∧  ¬  𝐶  ≤  ( 𝑇  ∨  𝑈 )  ∧  ¬  𝐶  ≤  ( 𝑈  ∨  𝑆 ) )  ∧  ( 𝐶  ≤  ( 𝑃  ∨  𝑆 )  ∧  𝐶  ≤  ( 𝑄  ∨  𝑇 )  ∧  𝐶  ≤  ( 𝑅  ∨  𝑈 ) ) ) ) )  | 
						
						
							| 2 | 
							
								
							 | 
							dalem.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							dalem.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							dalem.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							dalem.ps | 
							⊢ ( 𝜓  ↔  ( ( 𝑐  ∈  𝐴  ∧  𝑑  ∈  𝐴 )  ∧  ¬  𝑐  ≤  𝑌  ∧  ( 𝑑  ≠  𝑐  ∧  ¬  𝑑  ≤  𝑌  ∧  𝐶  ≤  ( 𝑐  ∨  𝑑 ) ) ) )  | 
						
						
							| 6 | 
							
								
							 | 
							dalem23.m | 
							⊢  ∧   =  ( meet ‘ 𝐾 )  | 
						
						
							| 7 | 
							
								
							 | 
							dalem23.o | 
							⊢ 𝑂  =  ( LPlanes ‘ 𝐾 )  | 
						
						
							| 8 | 
							
								
							 | 
							dalem23.y | 
							⊢ 𝑌  =  ( ( 𝑃  ∨  𝑄 )  ∨  𝑅 )  | 
						
						
							| 9 | 
							
								
							 | 
							dalem23.z | 
							⊢ 𝑍  =  ( ( 𝑆  ∨  𝑇 )  ∨  𝑈 )  | 
						
						
							| 10 | 
							
								
							 | 
							dalem23.g | 
							⊢ 𝐺  =  ( ( 𝑐  ∨  𝑃 )  ∧  ( 𝑑  ∨  𝑆 ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							oveq1i | 
							⊢ ( 𝐺  ∧  𝑌 )  =  ( ( ( 𝑐  ∨  𝑃 )  ∧  ( 𝑑  ∨  𝑆 ) )  ∧  𝑌 )  | 
						
						
							| 12 | 
							
								1
							 | 
							dalemkehl | 
							⊢ ( 𝜑  →  𝐾  ∈  HL )  | 
						
						
							| 13 | 
							
								
							 | 
							hlol | 
							⊢ ( 𝐾  ∈  HL  →  𝐾  ∈  OL )  | 
						
						
							| 14 | 
							
								12 13
							 | 
							syl | 
							⊢ ( 𝜑  →  𝐾  ∈  OL )  | 
						
						
							| 15 | 
							
								14
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝐾  ∈  OL )  | 
						
						
							| 16 | 
							
								12
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝐾  ∈  HL )  | 
						
						
							| 17 | 
							
								5
							 | 
							dalemccea | 
							⊢ ( 𝜓  →  𝑐  ∈  𝐴 )  | 
						
						
							| 18 | 
							
								17
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑐  ∈  𝐴 )  | 
						
						
							| 19 | 
							
								1
							 | 
							dalempea | 
							⊢ ( 𝜑  →  𝑃  ∈  𝐴 )  | 
						
						
							| 20 | 
							
								19
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑃  ∈  𝐴 )  | 
						
						
							| 21 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝐾 )  =  ( Base ‘ 𝐾 )  | 
						
						
							| 22 | 
							
								21 3 4
							 | 
							hlatjcl | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑐  ∈  𝐴  ∧  𝑃  ∈  𝐴 )  →  ( 𝑐  ∨  𝑃 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 23 | 
							
								16 18 20 22
							 | 
							syl3anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑐  ∨  𝑃 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 24 | 
							
								5
							 | 
							dalemddea | 
							⊢ ( 𝜓  →  𝑑  ∈  𝐴 )  | 
						
						
							| 25 | 
							
								24
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑑  ∈  𝐴 )  | 
						
						
							| 26 | 
							
								1
							 | 
							dalemsea | 
							⊢ ( 𝜑  →  𝑆  ∈  𝐴 )  | 
						
						
							| 27 | 
							
								26
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑆  ∈  𝐴 )  | 
						
						
							| 28 | 
							
								21 3 4
							 | 
							hlatjcl | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑑  ∈  𝐴  ∧  𝑆  ∈  𝐴 )  →  ( 𝑑  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 29 | 
							
								16 25 27 28
							 | 
							syl3anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑑  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 30 | 
							
								1 7
							 | 
							dalemyeb | 
							⊢ ( 𝜑  →  𝑌  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 31 | 
							
								30
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑌  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 32 | 
							
								21 6
							 | 
							latmmdir | 
							⊢ ( ( 𝐾  ∈  OL  ∧  ( ( 𝑐  ∨  𝑃 )  ∈  ( Base ‘ 𝐾 )  ∧  ( 𝑑  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 )  ∧  𝑌  ∈  ( Base ‘ 𝐾 ) ) )  →  ( ( ( 𝑐  ∨  𝑃 )  ∧  ( 𝑑  ∨  𝑆 ) )  ∧  𝑌 )  =  ( ( ( 𝑐  ∨  𝑃 )  ∧  𝑌 )  ∧  ( ( 𝑑  ∨  𝑆 )  ∧  𝑌 ) ) )  | 
						
						
							| 33 | 
							
								15 23 29 31 32
							 | 
							syl13anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( ( 𝑐  ∨  𝑃 )  ∧  ( 𝑑  ∨  𝑆 ) )  ∧  𝑌 )  =  ( ( ( 𝑐  ∨  𝑃 )  ∧  𝑌 )  ∧  ( ( 𝑑  ∨  𝑆 )  ∧  𝑌 ) ) )  | 
						
						
							| 34 | 
							
								11 33
							 | 
							eqtrid | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝐺  ∧  𝑌 )  =  ( ( ( 𝑐  ∨  𝑃 )  ∧  𝑌 )  ∧  ( ( 𝑑  ∨  𝑆 )  ∧  𝑌 ) ) )  | 
						
						
							| 35 | 
							
								3 4
							 | 
							hlatjcom | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑐  ∈  𝐴  ∧  𝑃  ∈  𝐴 )  →  ( 𝑐  ∨  𝑃 )  =  ( 𝑃  ∨  𝑐 ) )  | 
						
						
							| 36 | 
							
								16 18 20 35
							 | 
							syl3anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑐  ∨  𝑃 )  =  ( 𝑃  ∨  𝑐 ) )  | 
						
						
							| 37 | 
							
								36
							 | 
							oveq1d | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( 𝑐  ∨  𝑃 )  ∧  𝑌 )  =  ( ( 𝑃  ∨  𝑐 )  ∧  𝑌 ) )  | 
						
						
							| 38 | 
							
								1 2 3 4 7 8
							 | 
							dalemply | 
							⊢ ( 𝜑  →  𝑃  ≤  𝑌 )  | 
						
						
							| 39 | 
							
								38
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑃  ≤  𝑌 )  | 
						
						
							| 40 | 
							
								5
							 | 
							dalem-ccly | 
							⊢ ( 𝜓  →  ¬  𝑐  ≤  𝑌 )  | 
						
						
							| 41 | 
							
								40
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ¬  𝑐  ≤  𝑌 )  | 
						
						
							| 42 | 
							
								21 2 3 6 4
							 | 
							2atjm | 
							⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑐  ∈  𝐴  ∧  𝑌  ∈  ( Base ‘ 𝐾 ) )  ∧  ( 𝑃  ≤  𝑌  ∧  ¬  𝑐  ≤  𝑌 ) )  →  ( ( 𝑃  ∨  𝑐 )  ∧  𝑌 )  =  𝑃 )  | 
						
						
							| 43 | 
							
								16 20 18 31 39 41 42
							 | 
							syl132anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( 𝑃  ∨  𝑐 )  ∧  𝑌 )  =  𝑃 )  | 
						
						
							| 44 | 
							
								37 43
							 | 
							eqtrd | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( 𝑐  ∨  𝑃 )  ∧  𝑌 )  =  𝑃 )  | 
						
						
							| 45 | 
							
								3 4
							 | 
							hlatjcom | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑑  ∈  𝐴  ∧  𝑆  ∈  𝐴 )  →  ( 𝑑  ∨  𝑆 )  =  ( 𝑆  ∨  𝑑 ) )  | 
						
						
							| 46 | 
							
								16 25 27 45
							 | 
							syl3anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑑  ∨  𝑆 )  =  ( 𝑆  ∨  𝑑 ) )  | 
						
						
							| 47 | 
							
								46
							 | 
							oveq1d | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( 𝑑  ∨  𝑆 )  ∧  𝑌 )  =  ( ( 𝑆  ∨  𝑑 )  ∧  𝑌 ) )  | 
						
						
							| 48 | 
							
								1 2 3 4 9
							 | 
							dalemsly | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍 )  →  𝑆  ≤  𝑌 )  | 
						
						
							| 49 | 
							
								48
							 | 
							3adant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝑆  ≤  𝑌 )  | 
						
						
							| 50 | 
							
								5
							 | 
							dalem-ddly | 
							⊢ ( 𝜓  →  ¬  𝑑  ≤  𝑌 )  | 
						
						
							| 51 | 
							
								50
							 | 
							3ad2ant3 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ¬  𝑑  ≤  𝑌 )  | 
						
						
							| 52 | 
							
								21 2 3 6 4
							 | 
							2atjm | 
							⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑆  ∈  𝐴  ∧  𝑑  ∈  𝐴  ∧  𝑌  ∈  ( Base ‘ 𝐾 ) )  ∧  ( 𝑆  ≤  𝑌  ∧  ¬  𝑑  ≤  𝑌 ) )  →  ( ( 𝑆  ∨  𝑑 )  ∧  𝑌 )  =  𝑆 )  | 
						
						
							| 53 | 
							
								16 27 25 31 49 51 52
							 | 
							syl132anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( 𝑆  ∨  𝑑 )  ∧  𝑌 )  =  𝑆 )  | 
						
						
							| 54 | 
							
								47 53
							 | 
							eqtrd | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( 𝑑  ∨  𝑆 )  ∧  𝑌 )  =  𝑆 )  | 
						
						
							| 55 | 
							
								44 54
							 | 
							oveq12d | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ( ( 𝑐  ∨  𝑃 )  ∧  𝑌 )  ∧  ( ( 𝑑  ∨  𝑆 )  ∧  𝑌 ) )  =  ( 𝑃  ∧  𝑆 ) )  | 
						
						
							| 56 | 
							
								1 2 3 4 7 8
							 | 
							dalempnes | 
							⊢ ( 𝜑  →  𝑃  ≠  𝑆 )  | 
						
						
							| 57 | 
							
								
							 | 
							hlatl | 
							⊢ ( 𝐾  ∈  HL  →  𝐾  ∈  AtLat )  | 
						
						
							| 58 | 
							
								12 57
							 | 
							syl | 
							⊢ ( 𝜑  →  𝐾  ∈  AtLat )  | 
						
						
							| 59 | 
							
								
							 | 
							eqid | 
							⊢ ( 0. ‘ 𝐾 )  =  ( 0. ‘ 𝐾 )  | 
						
						
							| 60 | 
							
								6 59 4
							 | 
							atnem0 | 
							⊢ ( ( 𝐾  ∈  AtLat  ∧  𝑃  ∈  𝐴  ∧  𝑆  ∈  𝐴 )  →  ( 𝑃  ≠  𝑆  ↔  ( 𝑃  ∧  𝑆 )  =  ( 0. ‘ 𝐾 ) ) )  | 
						
						
							| 61 | 
							
								58 19 26 60
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( 𝑃  ≠  𝑆  ↔  ( 𝑃  ∧  𝑆 )  =  ( 0. ‘ 𝐾 ) ) )  | 
						
						
							| 62 | 
							
								56 61
							 | 
							mpbid | 
							⊢ ( 𝜑  →  ( 𝑃  ∧  𝑆 )  =  ( 0. ‘ 𝐾 ) )  | 
						
						
							| 63 | 
							
								62
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝑃  ∧  𝑆 )  =  ( 0. ‘ 𝐾 ) )  | 
						
						
							| 64 | 
							
								34 55 63
							 | 
							3eqtrd | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( 𝐺  ∧  𝑌 )  =  ( 0. ‘ 𝐾 ) )  | 
						
						
							| 65 | 
							
								58
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝐾  ∈  AtLat )  | 
						
						
							| 66 | 
							
								1 2 3 4 5 6 7 8 9 10
							 | 
							dalem23 | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  𝐺  ∈  𝐴 )  | 
						
						
							| 67 | 
							
								21 2 6 59 4
							 | 
							atnle | 
							⊢ ( ( 𝐾  ∈  AtLat  ∧  𝐺  ∈  𝐴  ∧  𝑌  ∈  ( Base ‘ 𝐾 ) )  →  ( ¬  𝐺  ≤  𝑌  ↔  ( 𝐺  ∧  𝑌 )  =  ( 0. ‘ 𝐾 ) ) )  | 
						
						
							| 68 | 
							
								65 66 31 67
							 | 
							syl3anc | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ( ¬  𝐺  ≤  𝑌  ↔  ( 𝐺  ∧  𝑌 )  =  ( 0. ‘ 𝐾 ) ) )  | 
						
						
							| 69 | 
							
								64 68
							 | 
							mpbird | 
							⊢ ( ( 𝜑  ∧  𝑌  =  𝑍  ∧  𝜓 )  →  ¬  𝐺  ≤  𝑌 )  |