| 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 2 4
							 | 
							latmle1 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑄  ∨  𝑇 )  ∈  ( Base ‘ 𝐾 )  ∧  ( 𝑃  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 ) )  →  ( ( 𝑄  ∨  𝑇 )  ∧  ( 𝑃  ∨  𝑆 ) )  ≤  ( 𝑄  ∨  𝑇 ) )  | 
						
						
							| 15 | 
							
								10 11 12 14
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( ( 𝑄  ∨  𝑇 )  ∧  ( 𝑃  ∨  𝑆 ) )  ≤  ( 𝑄  ∨  𝑇 ) )  | 
						
						
							| 16 | 
							
								9 15
							 | 
							eqbrtrid | 
							⊢ ( 𝜑  →  𝐶  ≤  ( 𝑄  ∨  𝑇 ) )  | 
						
						
							| 17 | 
							
								
							 | 
							simp13r | 
							⊢ ( ( ( ( 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 ) ) )  →  ¬  𝑄  ≤  𝑊 )  | 
						
						
							| 18 | 
							
								1 17
							 | 
							sylbi | 
							⊢ ( 𝜑  →  ¬  𝑄  ≤  𝑊 )  | 
						
						
							| 19 | 
							
								1
							 | 
							4atexlemkc | 
							⊢ ( 𝜑  →  𝐾  ∈  CvLat )  | 
						
						
							| 20 | 
							
								1 2 3 4 5 6 7 8
							 | 
							4atexlemv | 
							⊢ ( 𝜑  →  𝑉  ∈  𝐴 )  | 
						
						
							| 21 | 
							
								1
							 | 
							4atexlemq | 
							⊢ ( 𝜑  →  𝑄  ∈  𝐴 )  | 
						
						
							| 22 | 
							
								1
							 | 
							4atexlemt | 
							⊢ ( 𝜑  →  𝑇  ∈  𝐴 )  | 
						
						
							| 23 | 
							
								1 2 3 4 5 6 7
							 | 
							4atexlemu | 
							⊢ ( 𝜑  →  𝑈  ∈  𝐴 )  | 
						
						
							| 24 | 
							
								1 2 3 4 5 6 7 8
							 | 
							4atexlemunv | 
							⊢ ( 𝜑  →  𝑈  ≠  𝑉 )  | 
						
						
							| 25 | 
							
								1
							 | 
							4atexlemutvt | 
							⊢ ( 𝜑  →  ( 𝑈  ∨  𝑇 )  =  ( 𝑉  ∨  𝑇 ) )  | 
						
						
							| 26 | 
							
								5 3
							 | 
							cvlsupr6 | 
							⊢ ( ( 𝐾  ∈  CvLat  ∧  ( 𝑈  ∈  𝐴  ∧  𝑉  ∈  𝐴  ∧  𝑇  ∈  𝐴 )  ∧  ( 𝑈  ≠  𝑉  ∧  ( 𝑈  ∨  𝑇 )  =  ( 𝑉  ∨  𝑇 ) ) )  →  𝑇  ≠  𝑉 )  | 
						
						
							| 27 | 
							
								26
							 | 
							necomd | 
							⊢ ( ( 𝐾  ∈  CvLat  ∧  ( 𝑈  ∈  𝐴  ∧  𝑉  ∈  𝐴  ∧  𝑇  ∈  𝐴 )  ∧  ( 𝑈  ≠  𝑉  ∧  ( 𝑈  ∨  𝑇 )  =  ( 𝑉  ∨  𝑇 ) ) )  →  𝑉  ≠  𝑇 )  | 
						
						
							| 28 | 
							
								19 23 20 22 24 25 27
							 | 
							syl132anc | 
							⊢ ( 𝜑  →  𝑉  ≠  𝑇 )  | 
						
						
							| 29 | 
							
								2 3 5
							 | 
							cvlatexch2 | 
							⊢ ( ( 𝐾  ∈  CvLat  ∧  ( 𝑉  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑇  ∈  𝐴 )  ∧  𝑉  ≠  𝑇 )  →  ( 𝑉  ≤  ( 𝑄  ∨  𝑇 )  →  𝑄  ≤  ( 𝑉  ∨  𝑇 ) ) )  | 
						
						
							| 30 | 
							
								19 20 21 22 28 29
							 | 
							syl131anc | 
							⊢ ( 𝜑  →  ( 𝑉  ≤  ( 𝑄  ∨  𝑇 )  →  𝑄  ≤  ( 𝑉  ∨  𝑇 ) ) )  | 
						
						
							| 31 | 
							
								1 6
							 | 
							4atexlemwb | 
							⊢ ( 𝜑  →  𝑊  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 32 | 
							
								13 2 4
							 | 
							latmle2 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑃  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 )  ∧  𝑊  ∈  ( Base ‘ 𝐾 ) )  →  ( ( 𝑃  ∨  𝑆 )  ∧  𝑊 )  ≤  𝑊 )  | 
						
						
							| 33 | 
							
								10 12 31 32
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( ( 𝑃  ∨  𝑆 )  ∧  𝑊 )  ≤  𝑊 )  | 
						
						
							| 34 | 
							
								8 33
							 | 
							eqbrtrid | 
							⊢ ( 𝜑  →  𝑉  ≤  𝑊 )  | 
						
						
							| 35 | 
							
								1 2 3 4 5 6 7 8
							 | 
							4atexlemtlw | 
							⊢ ( 𝜑  →  𝑇  ≤  𝑊 )  | 
						
						
							| 36 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑉  ∈  𝐴  →  𝑉  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 37 | 
							
								20 36
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑉  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 38 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑇  ∈  𝐴  →  𝑇  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 39 | 
							
								22 38
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑇  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 40 | 
							
								13 2 3
							 | 
							latjle12 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑉  ∈  ( Base ‘ 𝐾 )  ∧  𝑇  ∈  ( Base ‘ 𝐾 )  ∧  𝑊  ∈  ( Base ‘ 𝐾 ) ) )  →  ( ( 𝑉  ≤  𝑊  ∧  𝑇  ≤  𝑊 )  ↔  ( 𝑉  ∨  𝑇 )  ≤  𝑊 ) )  | 
						
						
							| 41 | 
							
								10 37 39 31 40
							 | 
							syl13anc | 
							⊢ ( 𝜑  →  ( ( 𝑉  ≤  𝑊  ∧  𝑇  ≤  𝑊 )  ↔  ( 𝑉  ∨  𝑇 )  ≤  𝑊 ) )  | 
						
						
							| 42 | 
							
								34 35 41
							 | 
							mpbi2and | 
							⊢ ( 𝜑  →  ( 𝑉  ∨  𝑇 )  ≤  𝑊 )  | 
						
						
							| 43 | 
							
								13 5
							 | 
							atbase | 
							⊢ ( 𝑄  ∈  𝐴  →  𝑄  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 44 | 
							
								21 43
							 | 
							syl | 
							⊢ ( 𝜑  →  𝑄  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 45 | 
							
								1
							 | 
							4atexlemk | 
							⊢ ( 𝜑  →  𝐾  ∈  HL )  | 
						
						
							| 46 | 
							
								13 3 5
							 | 
							hlatjcl | 
							⊢ ( ( 𝐾  ∈  HL  ∧  𝑉  ∈  𝐴  ∧  𝑇  ∈  𝐴 )  →  ( 𝑉  ∨  𝑇 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 47 | 
							
								45 20 22 46
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( 𝑉  ∨  𝑇 )  ∈  ( Base ‘ 𝐾 ) )  | 
						
						
							| 48 | 
							
								13 2
							 | 
							lattr | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑄  ∈  ( Base ‘ 𝐾 )  ∧  ( 𝑉  ∨  𝑇 )  ∈  ( Base ‘ 𝐾 )  ∧  𝑊  ∈  ( Base ‘ 𝐾 ) ) )  →  ( ( 𝑄  ≤  ( 𝑉  ∨  𝑇 )  ∧  ( 𝑉  ∨  𝑇 )  ≤  𝑊 )  →  𝑄  ≤  𝑊 ) )  | 
						
						
							| 49 | 
							
								10 44 47 31 48
							 | 
							syl13anc | 
							⊢ ( 𝜑  →  ( ( 𝑄  ≤  ( 𝑉  ∨  𝑇 )  ∧  ( 𝑉  ∨  𝑇 )  ≤  𝑊 )  →  𝑄  ≤  𝑊 ) )  | 
						
						
							| 50 | 
							
								42 49
							 | 
							mpan2d | 
							⊢ ( 𝜑  →  ( 𝑄  ≤  ( 𝑉  ∨  𝑇 )  →  𝑄  ≤  𝑊 ) )  | 
						
						
							| 51 | 
							
								30 50
							 | 
							syld | 
							⊢ ( 𝜑  →  ( 𝑉  ≤  ( 𝑄  ∨  𝑇 )  →  𝑄  ≤  𝑊 ) )  | 
						
						
							| 52 | 
							
								18 51
							 | 
							mtod | 
							⊢ ( 𝜑  →  ¬  𝑉  ≤  ( 𝑄  ∨  𝑇 ) )  | 
						
						
							| 53 | 
							
								
							 | 
							nbrne2 | 
							⊢ ( ( 𝐶  ≤  ( 𝑄  ∨  𝑇 )  ∧  ¬  𝑉  ≤  ( 𝑄  ∨  𝑇 ) )  →  𝐶  ≠  𝑉 )  | 
						
						
							| 54 | 
							
								16 52 53
							 | 
							syl2anc | 
							⊢ ( 𝜑  →  𝐶  ≠  𝑉 )  | 
						
						
							| 55 | 
							
								1
							 | 
							4atexlemw | 
							⊢ ( 𝜑  →  𝑊  ∈  𝐻 )  | 
						
						
							| 56 | 
							
								45 55
							 | 
							jca | 
							⊢ ( 𝜑  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) )  | 
						
						
							| 57 | 
							
								1
							 | 
							4atexlempw | 
							⊢ ( 𝜑  →  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 ) )  | 
						
						
							| 58 | 
							
								1
							 | 
							4atexlems | 
							⊢ ( 𝜑  →  𝑆  ∈  𝐴 )  | 
						
						
							| 59 | 
							
								1 2 3 4 5 6 7 8 9
							 | 
							4atexlemc | 
							⊢ ( 𝜑  →  𝐶  ∈  𝐴 )  | 
						
						
							| 60 | 
							
								1 2 3 5
							 | 
							4atexlempns | 
							⊢ ( 𝜑  →  𝑃  ≠  𝑆 )  | 
						
						
							| 61 | 
							
								13 2 4
							 | 
							latmle2 | 
							⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑄  ∨  𝑇 )  ∈  ( Base ‘ 𝐾 )  ∧  ( 𝑃  ∨  𝑆 )  ∈  ( Base ‘ 𝐾 ) )  →  ( ( 𝑄  ∨  𝑇 )  ∧  ( 𝑃  ∨  𝑆 ) )  ≤  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 62 | 
							
								10 11 12 61
							 | 
							syl3anc | 
							⊢ ( 𝜑  →  ( ( 𝑄  ∨  𝑇 )  ∧  ( 𝑃  ∨  𝑆 ) )  ≤  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 63 | 
							
								9 62
							 | 
							eqbrtrid | 
							⊢ ( 𝜑  →  𝐶  ≤  ( 𝑃  ∨  𝑆 ) )  | 
						
						
							| 64 | 
							
								2 3 4 5 6 8
							 | 
							lhpat3 | 
							⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 ) )  ∧  ( 𝑆  ∈  𝐴  ∧  𝐶  ∈  𝐴 )  ∧  ( 𝑃  ≠  𝑆  ∧  𝐶  ≤  ( 𝑃  ∨  𝑆 ) ) )  →  ( ¬  𝐶  ≤  𝑊  ↔  𝐶  ≠  𝑉 ) )  | 
						
						
							| 65 | 
							
								56 57 58 59 60 63 64
							 | 
							syl222anc | 
							⊢ ( 𝜑  →  ( ¬  𝐶  ≤  𝑊  ↔  𝐶  ≠  𝑉 ) )  | 
						
						
							| 66 | 
							
								54 65
							 | 
							mpbird | 
							⊢ ( 𝜑  →  ¬  𝐶  ≤  𝑊 )  |