| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cdlemb.b | ⊢ 𝐵  =  ( Base ‘ 𝐾 ) | 
						
							| 2 |  | cdlemb.l | ⊢  ≤   =  ( le ‘ 𝐾 ) | 
						
							| 3 |  | cdlemb.j | ⊢  ∨   =  ( join ‘ 𝐾 ) | 
						
							| 4 |  | cdlemb.u | ⊢  1   =  ( 1. ‘ 𝐾 ) | 
						
							| 5 |  | cdlemb.c | ⊢ 𝐶  =  (  ⋖  ‘ 𝐾 ) | 
						
							| 6 |  | cdlemb.a | ⊢ 𝐴  =  ( Atoms ‘ 𝐾 ) | 
						
							| 7 |  | simp11 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝐾  ∈  HL ) | 
						
							| 8 |  | simp12 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝑃  ∈  𝐴 ) | 
						
							| 9 |  | simp13 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝑄  ∈  𝐴 ) | 
						
							| 10 |  | simp2l | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 11 |  | simp2r | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝑃  ≠  𝑄 ) | 
						
							| 12 |  | simp31 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝑋 𝐶  1  ) | 
						
							| 13 |  | simp32 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ¬  𝑃  ≤  𝑋 ) | 
						
							| 14 |  | eqid | ⊢ ( meet ‘ 𝐾 )  =  ( meet ‘ 𝐾 ) | 
						
							| 15 | 1 2 3 14 4 5 6 | 1cvrat | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≠  𝑄  ∧  𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋 ) )  →  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∈  𝐴 ) | 
						
							| 16 | 7 8 9 10 11 12 13 15 | syl133anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∈  𝐴 ) | 
						
							| 17 | 7 | hllatd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝐾  ∈  Lat ) | 
						
							| 18 | 1 6 | atbase | ⊢ ( 𝑃  ∈  𝐴  →  𝑃  ∈  𝐵 ) | 
						
							| 19 | 8 18 | syl | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝑃  ∈  𝐵 ) | 
						
							| 20 | 1 6 | atbase | ⊢ ( 𝑄  ∈  𝐴  →  𝑄  ∈  𝐵 ) | 
						
							| 21 | 9 20 | syl | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  𝑄  ∈  𝐵 ) | 
						
							| 22 | 1 3 | latjcl | ⊢ ( ( 𝐾  ∈  Lat  ∧  𝑃  ∈  𝐵  ∧  𝑄  ∈  𝐵 )  →  ( 𝑃  ∨  𝑄 )  ∈  𝐵 ) | 
						
							| 23 | 17 19 21 22 | syl3anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ( 𝑃  ∨  𝑄 )  ∈  𝐵 ) | 
						
							| 24 | 1 2 14 | latmle2 | ⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑃  ∨  𝑄 )  ∈  𝐵  ∧  𝑋  ∈  𝐵 )  →  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ≤  𝑋 ) | 
						
							| 25 | 17 23 10 24 | syl3anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ≤  𝑋 ) | 
						
							| 26 |  | eqid | ⊢ ( lt ‘ 𝐾 )  =  ( lt ‘ 𝐾 ) | 
						
							| 27 | 1 2 26 4 5 6 | 1cvratlt | ⊢ ( ( ( 𝐾  ∈  HL  ∧  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑋 𝐶  1   ∧  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ≤  𝑋 ) )  →  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 ) ( lt ‘ 𝐾 ) 𝑋 ) | 
						
							| 28 | 7 16 10 12 25 27 | syl32anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 ) ( lt ‘ 𝐾 ) 𝑋 ) | 
						
							| 29 | 1 26 6 | 2atlt | ⊢ ( ( ( 𝐾  ∈  HL  ∧  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 ) ( lt ‘ 𝐾 ) 𝑋 )  →  ∃ 𝑢  ∈  𝐴 ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) | 
						
							| 30 | 7 16 10 28 29 | syl31anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ∃ 𝑢  ∈  𝐴 ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) | 
						
							| 31 |  | simpl11 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  𝐾  ∈  HL ) | 
						
							| 32 |  | simpl12 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  𝑃  ∈  𝐴 ) | 
						
							| 33 |  | simprl | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  𝑢  ∈  𝐴 ) | 
						
							| 34 |  | simpl32 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  ¬  𝑃  ≤  𝑋 ) | 
						
							| 35 |  | simprrr | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) | 
						
							| 36 |  | simpl2l | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 37 | 2 26 | pltle | ⊢ ( ( 𝐾  ∈  HL  ∧  𝑢  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  →  ( 𝑢 ( lt ‘ 𝐾 ) 𝑋  →  𝑢  ≤  𝑋 ) ) | 
						
							| 38 | 31 33 36 37 | syl3anc | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  ( 𝑢 ( lt ‘ 𝐾 ) 𝑋  →  𝑢  ≤  𝑋 ) ) | 
						
							| 39 | 35 38 | mpd | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  𝑢  ≤  𝑋 ) | 
						
							| 40 |  | breq1 | ⊢ ( 𝑃  =  𝑢  →  ( 𝑃  ≤  𝑋  ↔  𝑢  ≤  𝑋 ) ) | 
						
							| 41 | 39 40 | syl5ibrcom | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  ( 𝑃  =  𝑢  →  𝑃  ≤  𝑋 ) ) | 
						
							| 42 | 41 | necon3bd | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  ( ¬  𝑃  ≤  𝑋  →  𝑃  ≠  𝑢 ) ) | 
						
							| 43 | 34 42 | mpd | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  𝑃  ≠  𝑢 ) | 
						
							| 44 | 2 3 6 | hlsupr | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑢  ∈  𝐴 )  ∧  𝑃  ≠  𝑢 )  →  ∃ 𝑟  ∈  𝐴 ( 𝑟  ≠  𝑃  ∧  𝑟  ≠  𝑢  ∧  𝑟  ≤  ( 𝑃  ∨  𝑢 ) ) ) | 
						
							| 45 | 31 32 33 43 44 | syl31anc | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  ∃ 𝑟  ∈  𝐴 ( 𝑟  ≠  𝑃  ∧  𝑟  ≠  𝑢  ∧  𝑟  ≤  ( 𝑃  ∨  𝑢 ) ) ) | 
						
							| 46 |  | eqid | ⊢ ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  =  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 ) | 
						
							| 47 | 1 2 3 4 5 6 26 14 46 | cdlemblem | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) )  ∧  ( 𝑟  ∈  𝐴  ∧  ( 𝑟  ≠  𝑃  ∧  𝑟  ≠  𝑢  ∧  𝑟  ≤  ( 𝑃  ∨  𝑢 ) ) ) )  →  ( ¬  𝑟  ≤  𝑋  ∧  ¬  𝑟  ≤  ( 𝑃  ∨  𝑄 ) ) ) | 
						
							| 48 | 47 | 3exp | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ( ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) )  →  ( ( 𝑟  ∈  𝐴  ∧  ( 𝑟  ≠  𝑃  ∧  𝑟  ≠  𝑢  ∧  𝑟  ≤  ( 𝑃  ∨  𝑢 ) ) )  →  ( ¬  𝑟  ≤  𝑋  ∧  ¬  𝑟  ≤  ( 𝑃  ∨  𝑄 ) ) ) ) ) | 
						
							| 49 | 48 | exp4a | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ( ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) )  →  ( 𝑟  ∈  𝐴  →  ( ( 𝑟  ≠  𝑃  ∧  𝑟  ≠  𝑢  ∧  𝑟  ≤  ( 𝑃  ∨  𝑢 ) )  →  ( ¬  𝑟  ≤  𝑋  ∧  ¬  𝑟  ≤  ( 𝑃  ∨  𝑄 ) ) ) ) ) ) | 
						
							| 50 | 49 | imp | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  ( 𝑟  ∈  𝐴  →  ( ( 𝑟  ≠  𝑃  ∧  𝑟  ≠  𝑢  ∧  𝑟  ≤  ( 𝑃  ∨  𝑢 ) )  →  ( ¬  𝑟  ≤  𝑋  ∧  ¬  𝑟  ≤  ( 𝑃  ∨  𝑄 ) ) ) ) ) | 
						
							| 51 | 50 | reximdvai | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  ( ∃ 𝑟  ∈  𝐴 ( 𝑟  ≠  𝑃  ∧  𝑟  ≠  𝑢  ∧  𝑟  ≤  ( 𝑃  ∨  𝑢 ) )  →  ∃ 𝑟  ∈  𝐴 ( ¬  𝑟  ≤  𝑋  ∧  ¬  𝑟  ≤  ( 𝑃  ∨  𝑄 ) ) ) ) | 
						
							| 52 | 45 51 | mpd | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  ∧  ( 𝑢  ∈  𝐴  ∧  ( 𝑢  ≠  ( ( 𝑃  ∨  𝑄 ) ( meet ‘ 𝐾 ) 𝑋 )  ∧  𝑢 ( lt ‘ 𝐾 ) 𝑋 ) ) )  →  ∃ 𝑟  ∈  𝐴 ( ¬  𝑟  ≤  𝑋  ∧  ¬  𝑟  ≤  ( 𝑃  ∨  𝑄 ) ) ) | 
						
							| 53 | 30 52 | rexlimddv | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  ∧  ( 𝑋  ∈  𝐵  ∧  𝑃  ≠  𝑄 )  ∧  ( 𝑋 𝐶  1   ∧  ¬  𝑃  ≤  𝑋  ∧  ¬  𝑄  ≤  𝑋 ) )  →  ∃ 𝑟  ∈  𝐴 ( ¬  𝑟  ≤  𝑋  ∧  ¬  𝑟  ≤  ( 𝑃  ∨  𝑄 ) ) ) |