| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							4thatlem.ph | 
							⊢ ( 𝜑  ↔  ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  ( 𝑄  ∈  𝐴  ∧  ¬  𝑄  ≤  𝑊 ) )  ∧  ( 𝑆  ∈  𝐴  ∧  ( 𝑅  ∈  𝐴  ∧  ¬  𝑅  ≤  𝑊  ∧  ( 𝑃  ∨  𝑅 )  =  ( 𝑄  ∨  𝑅 ) )  ∧  ( 𝑇  ∈  𝐴  ∧  ( 𝑈  ∨  𝑇 )  =  ( 𝑉  ∨  𝑇 ) ) )  ∧  ( 𝑃  ≠  𝑄  ∧  ¬  𝑆  ≤  ( 𝑃  ∨  𝑄 ) ) ) )  | 
						
						
							| 2 | 
							
								
							 | 
							4thatlem0.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							4thatlem0.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							4thatlem0.m | 
							⊢  ∧   =  ( meet ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							4thatlem0.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 6 | 
							
								
							 | 
							4thatlem0.h | 
							⊢ 𝐻  =  ( LHyp ‘ 𝐾 )  | 
						
						
							| 7 | 
							
								
							 | 
							4thatlem0.u | 
							⊢ 𝑈  =  ( ( 𝑃  ∨  𝑄 )  ∧  𝑊 )  | 
						
						
							| 8 | 
							
								
							 | 
							4thatlem0.v | 
							⊢ 𝑉  =  ( ( 𝑃  ∨  𝑆 )  ∧  𝑊 )  | 
						
						
							| 9 | 
							
								
							 | 
							4thatlem0.c | 
							⊢ 𝐶  =  ( ( 𝑄  ∨  𝑇 )  ∧  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 10 | 
							
								1
							 | 
							4atexlemkl | 
							⊢ ( 𝜑  →  𝐾  ∈  Lat )  | 
						
						
							| 11 | 
							
								1 3 5
							 | 
							4atexlemqtb | 
							⊢ ( 𝜑  →  ( 𝑄  ∨  𝑇 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 12 | 
							
								1 3 5
							 | 
							4atexlempsb | 
							⊢ ( 𝜑  →  ( 𝑃  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 13 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝐾 )  =  ( Base ‘ 𝐾 )  | 
						
						
							| 14 | 
							
								13 4
							 | 
							latmcom | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑄  ∨  𝑇 )  ∈  ( Base ‘ 𝐾 )  ∧  ( 𝑃  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 ) )  →  ( ( 𝑄  ∨  𝑇 )  ∧  ( 𝑃  ∨  𝑆 ) )  =  ( ( 𝑃  ∨  𝑆 )  ∧  ( 𝑄  ∨  𝑇 ) ) )  | 
						
						
							| 15 | 
							
								10 11 12 14
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( ( 𝑄  ∨  𝑇 )  ∧  ( 𝑃  ∨  𝑆 ) )  =  ( ( 𝑃  ∨  𝑆 )  ∧  ( 𝑄  ∨  𝑇 ) ) )  | 
						
						
							| 16 | 
							
								9 15
							 | 
							eqtrid | 
							⊢ ( 𝜑  →  𝐶  =  ( ( 𝑃  ∨  𝑆 )  ∧  ( 𝑄  ∨  𝑇 ) ) )  | 
						
						
							| 17 | 
							
								1
							 | 
							4atexlemk | 
							⊢ ( 𝜑  →  𝐾  ∈  HL )  | 
						
						
							| 18 | 
							
								1
							 | 
							4atexlemp | 
							⊢ ( 𝜑  →  𝑃  ∈  𝐴 )  | 
						
						
							| 19 | 
							
								1
							 | 
							4atexlems | 
							⊢ ( 𝜑  →  𝑆  ∈  𝐴 )  | 
						
						
							| 20 | 
							
								1
							 | 
							4atexlemq | 
							⊢ ( 𝜑  →  𝑄  ∈  𝐴 )  | 
						
						
							| 21 | 
							
								1
							 | 
							4atexlemt | 
							⊢ ( 𝜑  →  𝑇  ∈  𝐴 )  | 
						
						
							| 22 | 
							
								1 2 3 5
							 | 
							4atexlempns | 
							⊢ ( 𝜑  →  𝑃  ≠  𝑆 )  | 
						
						
							| 23 | 
							
								1 2 3 4 5 6 7 8
							 | 
							4atexlemntlpq | 
							⊢ ( 𝜑  →  ¬  𝑇  ≤  ( 𝑃  ∨  𝑄 ) )  | 
						
						
							| 24 | 
							
								2 3 5
							 | 
							atnlej2 | 
							⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑇  ∈  𝐴  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ¬  𝑇  ≤  ( 𝑃  ∨  𝑄 ) )  →  𝑇  ≠  𝑄 )  | 
						
						
							| 25 | 
							
								24
							 | 
							necomd | 
							⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑇  ∈  𝐴  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ¬  𝑇  ≤  ( 𝑃  ∨  𝑄 ) )  →  𝑄  ≠  𝑇 )  | 
						
						
							| 26 | 
							
								17 21 18 20 23 25
							 | 
							syl131anc | 
							⊢ ( 𝜑  →  𝑄  ≠  𝑇 )  | 
						
						
							| 27 | 
							
								1
							 | 
							4atexlempnq | 
							⊢ ( 𝜑  →  𝑃  ≠  𝑄 )  | 
						
						
							| 28 | 
							
								1
							 | 
							4atexlemnslpq | 
							⊢ ( 𝜑  →  ¬  𝑆  ≤  ( 𝑃  ∨  𝑄 ) )  | 
						
						
							| 29 | 
							
								2 3 5
							 | 
							4atlem0ae | 
							⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑆  ∈  𝐴 )  ∧  ( 𝑃  ≠  𝑄  ∧  ¬  𝑆  ≤  ( 𝑃  ∨  𝑄 ) ) )  →  ¬  𝑄  ≤  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 30 | 
							
								17 18 20 19 27 28 29
							 | 
							syl132anc | 
							⊢ ( 𝜑  →  ¬  𝑄  ≤  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 31 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑇  ∈  𝐴  →  𝑇  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 32 | 
							
								21 31
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑇  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 33 | 
							
								1 2 3 4 5 6 7
							 | 
							4atexlemu | 
							⊢ ( 𝜑  →  𝑈  ∈  𝐴 )  | 
						
						
							| 34 | 
							
								1 2 3 4 5 6 7 8
							 | 
							4atexlemv | 
							⊢ ( 𝜑  →  𝑉  ∈  𝐴 )  | 
						
						
							| 35 | 
							
								13 3 5
							 | 
							hlatjcl | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑈  ∈  𝐴  ∧  𝑉  ∈  𝐴 )  →  ( 𝑈  ∨  𝑉 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 36 | 
							
								17 33 34 35
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( 𝑈  ∨  𝑉 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 37 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑄  ∈  𝐴  →  𝑄  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 38 | 
							
								20 37
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑄  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 39 | 
							
								13 3
							 | 
							latjcl | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑃  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 )  ∧  𝑄  ∈  ( Base ‘ 𝐾 ) )  →  ( ( 𝑃  ∨  𝑆 )  ∨  𝑄 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 40 | 
							
								10 12 38 39
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( ( 𝑃  ∨  𝑆 )  ∨  𝑄 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 41 | 
							
								1
							 | 
							4atexlemkc | 
							⊢ ( 𝜑  →  𝐾  ∈  CvLat )  | 
						
						
							| 42 | 
							
								1 2 3 4 5 6 7 8
							 | 
							4atexlemunv | 
							⊢ ( 𝜑  →  𝑈  ≠  𝑉 )  | 
						
						
							| 43 | 
							
								1
							 | 
							4atexlemutvt | 
							⊢ ( 𝜑  →  ( 𝑈  ∨  𝑇 )  =  ( 𝑉  ∨  𝑇 ) )  | 
						
						
							| 44 | 
							
								5 2 3
							 | 
							cvlsupr4 | 
							⊢ ( ( 𝐾  ∈  CvLat  ∧  ( 𝑈  ∈  𝐴  ∧  𝑉  ∈  𝐴  ∧  𝑇  ∈  𝐴 )  ∧  ( 𝑈  ≠  𝑉  ∧  ( 𝑈  ∨  𝑇 )  =  ( 𝑉  ∨  𝑇 ) ) )  →  𝑇  ≤  ( 𝑈  ∨  𝑉 ) )  | 
						
						
							| 45 | 
							
								41 33 34 21 42 43 44
							 | 
							syl132anc | 
							⊢ ( 𝜑  →  𝑇  ≤  ( 𝑈  ∨  𝑉 ) )  | 
						
						
							| 46 | 
							
								13 3 5
							 | 
							hlatjcl | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  →  ( 𝑃  ∨  𝑄 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 47 | 
							
								17 18 20 46
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( 𝑃  ∨  𝑄 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 48 | 
							
								1 6
							 | 
							4atexlemwb | 
							⊢ ( 𝜑  →  𝑊  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 49 | 
							
								13 2 4
							 | 
							latmle1 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑃  ∨  𝑄 )  ∈  ( Base ‘ 𝐾 )  ∧  𝑊  ∈  ( Base ‘ 𝐾 ) )  →  ( ( 𝑃  ∨  𝑄 )  ∧  𝑊 )  ≤  ( 𝑃  ∨  𝑄 ) )  | 
						
						
							| 50 | 
							
								10 47 48 49
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( ( 𝑃  ∨  𝑄 )  ∧  𝑊 )  ≤  ( 𝑃  ∨  𝑄 ) )  | 
						
						
							| 51 | 
							
								7 50
							 | 
							eqbrtrid | 
							⊢ ( 𝜑  →  𝑈  ≤  ( 𝑃  ∨  𝑄 ) )  | 
						
						
							| 52 | 
							
								13 2 4
							 | 
							latmle1 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑃  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 )  ∧  𝑊  ∈  ( Base ‘ 𝐾 ) )  →  ( ( 𝑃  ∨  𝑆 )  ∧  𝑊 )  ≤  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 53 | 
							
								10 12 48 52
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( ( 𝑃  ∨  𝑆 )  ∧  𝑊 )  ≤  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 54 | 
							
								8 53
							 | 
							eqbrtrid | 
							⊢ ( 𝜑  →  𝑉  ≤  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 55 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑈  ∈  𝐴  →  𝑈  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 56 | 
							
								33 55
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑈  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 57 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑉  ∈  𝐴  →  𝑉  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 58 | 
							
								34 57
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑉  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 59 | 
							
								13 2 3
							 | 
							latjlej12 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑈  ∈  ( Base ‘ 𝐾 )  ∧  ( 𝑃  ∨  𝑄 )  ∈  ( Base ‘ 𝐾 ) )  ∧  ( 𝑉  ∈  ( Base ‘ 𝐾 )  ∧  ( 𝑃  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 ) ) )  →  ( ( 𝑈  ≤  ( 𝑃  ∨  𝑄 )  ∧  𝑉  ≤  ( 𝑃  ∨  𝑆 ) )  →  ( 𝑈  ∨  𝑉 )  ≤  ( ( 𝑃  ∨  𝑄 )  ∨  ( 𝑃  ∨  𝑆 ) ) ) )  | 
						
						
							| 60 | 
							
								10 56 47 58 12 59
							 | 
							syl122anc | 
							⊢ ( 𝜑  →  ( ( 𝑈  ≤  ( 𝑃  ∨  𝑄 )  ∧  𝑉  ≤  ( 𝑃  ∨  𝑆 ) )  →  ( 𝑈  ∨  𝑉 )  ≤  ( ( 𝑃  ∨  𝑄 )  ∨  ( 𝑃  ∨  𝑆 ) ) ) )  | 
						
						
							| 61 | 
							
								51 54 60
							 | 
							mp2and | 
							⊢ ( 𝜑  →  ( 𝑈  ∨  𝑉 )  ≤  ( ( 𝑃  ∨  𝑄 )  ∨  ( 𝑃  ∨  𝑆 ) ) )  | 
						
						
							| 62 | 
							
								3 5
							 | 
							hlatjass | 
							⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑆  ∈  𝐴 ) )  →  ( ( 𝑃  ∨  𝑄 )  ∨  𝑆 )  =  ( 𝑃  ∨  ( 𝑄  ∨  𝑆 ) ) )  | 
						
						
							| 63 | 
							
								17 18 20 19 62
							 | 
							syl13anc | 
							⊢ ( 𝜑  →  ( ( 𝑃  ∨  𝑄 )  ∨  𝑆 )  =  ( 𝑃  ∨  ( 𝑄  ∨  𝑆 ) ) )  | 
						
						
							| 64 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑃  ∈  𝐴  →  𝑃  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 65 | 
							
								18 64
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑃  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 66 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑆  ∈  𝐴  →  𝑆  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 67 | 
							
								19 66
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑆  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 68 | 
							
								13 3
							 | 
							latj32 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑃  ∈  ( Base ‘ 𝐾 )  ∧  𝑄  ∈  ( Base ‘ 𝐾 )  ∧  𝑆  ∈  ( Base ‘ 𝐾 ) ) )  →  ( ( 𝑃  ∨  𝑄 )  ∨  𝑆 )  =  ( ( 𝑃  ∨  𝑆 )  ∨  𝑄 ) )  | 
						
						
							| 69 | 
							
								10 65 38 67 68
							 | 
							syl13anc | 
							⊢ ( 𝜑  →  ( ( 𝑃  ∨  𝑄 )  ∨  𝑆 )  =  ( ( 𝑃  ∨  𝑆 )  ∨  𝑄 ) )  | 
						
						
							| 70 | 
							
								13 3
							 | 
							latjjdi | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑃  ∈  ( Base ‘ 𝐾 )  ∧  𝑄  ∈  ( Base ‘ 𝐾 )  ∧  𝑆  ∈  ( Base ‘ 𝐾 ) ) )  →  ( 𝑃  ∨  ( 𝑄  ∨  𝑆 ) )  =  ( ( 𝑃  ∨  𝑄 )  ∨  ( 𝑃  ∨  𝑆 ) ) )  | 
						
						
							| 71 | 
							
								10 65 38 67 70
							 | 
							syl13anc | 
							⊢ ( 𝜑  →  ( 𝑃  ∨  ( 𝑄  ∨  𝑆 ) )  =  ( ( 𝑃  ∨  𝑄 )  ∨  ( 𝑃  ∨  𝑆 ) ) )  | 
						
						
							| 72 | 
							
								63 69 71
							 | 
							3eqtr3rd | 
							⊢ ( 𝜑  →  ( ( 𝑃  ∨  𝑄 )  ∨  ( 𝑃  ∨  𝑆 ) )  =  ( ( 𝑃  ∨  𝑆 )  ∨  𝑄 ) )  | 
						
						
							| 73 | 
							
								61 72
							 | 
							breqtrd | 
							⊢ ( 𝜑  →  ( 𝑈  ∨  𝑉 )  ≤  ( ( 𝑃  ∨  𝑆 )  ∨  𝑄 ) )  | 
						
						
							| 74 | 
							
								13 2 10 32 36 40 45 73
							 | 
							lattrd | 
							⊢ ( 𝜑  →  𝑇  ≤  ( ( 𝑃  ∨  𝑆 )  ∨  𝑄 ) )  | 
						
						
							| 75 | 
							
								2 3 4 5
							 | 
							2atmat | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑆  ∈  𝐴 )  ∧  ( 𝑄  ∈  𝐴  ∧  𝑇  ∈  𝐴  ∧  𝑃  ≠  𝑆 )  ∧  ( 𝑄  ≠  𝑇  ∧  ¬  𝑄  ≤  ( 𝑃  ∨  𝑆 )  ∧  𝑇  ≤  ( ( 𝑃  ∨  𝑆 )  ∨  𝑄 ) ) )  →  ( ( 𝑃  ∨  𝑆 )  ∧  ( 𝑄  ∨  𝑇 ) )  ∈  𝐴 )  | 
						
						
							| 76 | 
							
								17 18 19 20 21 22 26 30 74 75
							 | 
							syl333anc | 
							⊢ ( 𝜑  →  ( ( 𝑃  ∨  𝑆 )  ∧  ( 𝑄  ∨  𝑇 ) )  ∈  𝐴 )  | 
						
						
							| 77 | 
							
								16 76
							 | 
							eqeltrd | 
							⊢ ( 𝜑  →  𝐶  ∈  𝐴 )  |