| Step | Hyp | Ref | Expression | 
						
							| 1 |  | osumcllem.l | ⊢  ≤   =  ( le ‘ 𝐾 ) | 
						
							| 2 |  | osumcllem.j | ⊢  ∨   =  ( join ‘ 𝐾 ) | 
						
							| 3 |  | osumcllem.a | ⊢ 𝐴  =  ( Atoms ‘ 𝐾 ) | 
						
							| 4 |  | osumcllem.p | ⊢  +   =  ( +𝑃 ‘ 𝐾 ) | 
						
							| 5 |  | osumcllem.o | ⊢  ⊥   =  ( ⊥𝑃 ‘ 𝐾 ) | 
						
							| 6 |  | osumcllem.c | ⊢ 𝐶  =  ( PSubCl ‘ 𝐾 ) | 
						
							| 7 |  | osumcllem.m | ⊢ 𝑀  =  ( 𝑋  +  { 𝑝 } ) | 
						
							| 8 |  | osumcllem.u | ⊢ 𝑈  =  (  ⊥  ‘ (  ⊥  ‘ ( 𝑋  +  𝑌 ) ) ) | 
						
							| 9 |  | simp11 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  𝐾  ∈  HL ) | 
						
							| 10 | 9 | hllatd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  𝐾  ∈  Lat ) | 
						
							| 11 |  | simp12 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  𝑋  ⊆  𝐴 ) | 
						
							| 12 |  | simp23 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  𝑝  ∈  𝐴 ) | 
						
							| 13 |  | simp22 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  𝑋  ≠  ∅ ) | 
						
							| 14 |  | inss2 | ⊢ ( 𝑌  ∩  𝑀 )  ⊆  𝑀 | 
						
							| 15 | 14 | sseli | ⊢ ( 𝑞  ∈  ( 𝑌  ∩  𝑀 )  →  𝑞  ∈  𝑀 ) | 
						
							| 16 | 15 | 3ad2ant3 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  𝑞  ∈  𝑀 ) | 
						
							| 17 | 16 7 | eleqtrdi | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  𝑞  ∈  ( 𝑋  +  { 𝑝 } ) ) | 
						
							| 18 | 1 2 3 4 | elpaddatiN | ⊢ ( ( ( 𝐾  ∈  Lat  ∧  𝑋  ⊆  𝐴  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑋  ≠  ∅  ∧  𝑞  ∈  ( 𝑋  +  { 𝑝 } ) ) )  →  ∃ 𝑟  ∈  𝑋 𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) | 
						
							| 19 | 10 11 12 13 17 18 | syl32anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  ∃ 𝑟  ∈  𝑋 𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) | 
						
							| 20 |  | simp11 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  ∧  𝑟  ∈  𝑋  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) )  →  ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 ) ) | 
						
							| 21 |  | simp121 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  ∧  𝑟  ∈  𝑋  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) )  →  𝑋  ⊆  (  ⊥  ‘ 𝑌 ) ) | 
						
							| 22 |  | simp123 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  ∧  𝑟  ∈  𝑋  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) )  →  𝑝  ∈  𝐴 ) | 
						
							| 23 |  | simp2 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  ∧  𝑟  ∈  𝑋  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) )  →  𝑟  ∈  𝑋 ) | 
						
							| 24 |  | inss1 | ⊢ ( 𝑌  ∩  𝑀 )  ⊆  𝑌 | 
						
							| 25 |  | simp13 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  ∧  𝑟  ∈  𝑋  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) )  →  𝑞  ∈  ( 𝑌  ∩  𝑀 ) ) | 
						
							| 26 | 24 25 | sselid | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  ∧  𝑟  ∈  𝑋  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) )  →  𝑞  ∈  𝑌 ) | 
						
							| 27 |  | simp3 | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  ∧  𝑟  ∈  𝑋  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) )  →  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) | 
						
							| 28 | 1 2 3 4 5 6 7 8 | osumcllem6N | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑝  ∈  ( 𝑋  +  𝑌 ) ) | 
						
							| 29 | 20 21 22 23 26 27 28 | syl123anc | ⊢ ( ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  ∧  𝑟  ∈  𝑋  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) )  →  𝑝  ∈  ( 𝑋  +  𝑌 ) ) | 
						
							| 30 | 29 | rexlimdv3a | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  ( ∃ 𝑟  ∈  𝑋 𝑞  ≤  ( 𝑟  ∨  𝑝 )  →  𝑝  ∈  ( 𝑋  +  𝑌 ) ) ) | 
						
							| 31 | 19 30 | mpd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑋  ≠  ∅  ∧  𝑝  ∈  𝐴 )  ∧  𝑞  ∈  ( 𝑌  ∩  𝑀 ) )  →  𝑝  ∈  ( 𝑋  +  𝑌 ) ) |