| Step | Hyp | Ref | Expression | 
						
							| 1 |  | atlelt.b | ⊢ 𝐵  =  ( Base ‘ 𝐾 ) | 
						
							| 2 |  | atlelt.l | ⊢  ≤   =  ( le ‘ 𝐾 ) | 
						
							| 3 |  | atlelt.s | ⊢  <   =  ( lt ‘ 𝐾 ) | 
						
							| 4 |  | atlelt.a | ⊢ 𝐴  =  ( Atoms ‘ 𝐾 ) | 
						
							| 5 |  | simp3r | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑄  <  𝑋 ) | 
						
							| 6 |  | breq1 | ⊢ ( 𝑃  =  𝑄  →  ( 𝑃  <  𝑋  ↔  𝑄  <  𝑋 ) ) | 
						
							| 7 | 5 6 | syl5ibrcom | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( 𝑃  =  𝑄  →  𝑃  <  𝑋 ) ) | 
						
							| 8 |  | simp1 | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝐾  ∈  HL ) | 
						
							| 9 |  | simp21 | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑃  ∈  𝐴 ) | 
						
							| 10 |  | simp22 | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑄  ∈  𝐴 ) | 
						
							| 11 |  | eqid | ⊢ ( join ‘ 𝐾 )  =  ( join ‘ 𝐾 ) | 
						
							| 12 | 3 11 4 | atlt | ⊢ ( ( 𝐾  ∈  HL  ∧  𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴 )  →  ( 𝑃  <  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ↔  𝑃  ≠  𝑄 ) ) | 
						
							| 13 | 8 9 10 12 | syl3anc | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( 𝑃  <  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ↔  𝑃  ≠  𝑄 ) ) | 
						
							| 14 |  | simp3l | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑃  ≤  𝑋 ) | 
						
							| 15 |  | simp23 | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 16 | 8 10 15 | 3jca | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( 𝐾  ∈  HL  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 ) ) | 
						
							| 17 | 2 3 | pltle | ⊢ ( ( 𝐾  ∈  HL  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  →  ( 𝑄  <  𝑋  →  𝑄  ≤  𝑋 ) ) | 
						
							| 18 | 16 5 17 | sylc | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑄  ≤  𝑋 ) | 
						
							| 19 |  | hllat | ⊢ ( 𝐾  ∈  HL  →  𝐾  ∈  Lat ) | 
						
							| 20 | 19 | 3ad2ant1 | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝐾  ∈  Lat ) | 
						
							| 21 | 1 4 | atbase | ⊢ ( 𝑃  ∈  𝐴  →  𝑃  ∈  𝐵 ) | 
						
							| 22 | 9 21 | syl | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑃  ∈  𝐵 ) | 
						
							| 23 | 1 4 | atbase | ⊢ ( 𝑄  ∈  𝐴  →  𝑄  ∈  𝐵 ) | 
						
							| 24 | 10 23 | syl | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑄  ∈  𝐵 ) | 
						
							| 25 | 1 2 11 | latjle12 | ⊢ ( ( 𝐾  ∈  Lat  ∧  ( 𝑃  ∈  𝐵  ∧  𝑄  ∈  𝐵  ∧  𝑋  ∈  𝐵 ) )  →  ( ( 𝑃  ≤  𝑋  ∧  𝑄  ≤  𝑋 )  ↔  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ≤  𝑋 ) ) | 
						
							| 26 | 20 22 24 15 25 | syl13anc | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( ( 𝑃  ≤  𝑋  ∧  𝑄  ≤  𝑋 )  ↔  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ≤  𝑋 ) ) | 
						
							| 27 | 14 18 26 | mpbi2and | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ≤  𝑋 ) | 
						
							| 28 |  | hlpos | ⊢ ( 𝐾  ∈  HL  →  𝐾  ∈  Poset ) | 
						
							| 29 | 28 | 3ad2ant1 | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝐾  ∈  Poset ) | 
						
							| 30 | 1 11 | latjcl | ⊢ ( ( 𝐾  ∈  Lat  ∧  𝑃  ∈  𝐵  ∧  𝑄  ∈  𝐵 )  →  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ∈  𝐵 ) | 
						
							| 31 | 20 22 24 30 | syl3anc | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ∈  𝐵 ) | 
						
							| 32 | 1 2 3 | pltletr | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑃  ∈  𝐵  ∧  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ∈  𝐵  ∧  𝑋  ∈  𝐵 ) )  →  ( ( 𝑃  <  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ∧  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ≤  𝑋 )  →  𝑃  <  𝑋 ) ) | 
						
							| 33 | 29 22 31 15 32 | syl13anc | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( ( 𝑃  <  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ∧  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  ≤  𝑋 )  →  𝑃  <  𝑋 ) ) | 
						
							| 34 | 27 33 | mpan2d | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( 𝑃  <  ( 𝑃 ( join ‘ 𝐾 ) 𝑄 )  →  𝑃  <  𝑋 ) ) | 
						
							| 35 | 13 34 | sylbird | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  ( 𝑃  ≠  𝑄  →  𝑃  <  𝑋 ) ) | 
						
							| 36 | 7 35 | pm2.61dne | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑃  ∈  𝐴  ∧  𝑄  ∈  𝐴  ∧  𝑋  ∈  𝐵 )  ∧  ( 𝑃  ≤  𝑋  ∧  𝑄  <  𝑋 ) )  →  𝑃  <  𝑋 ) |