| 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 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝐾  ∈  HL ) | 
						
							| 10 |  | simp12 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑋  ⊆  𝐴 ) | 
						
							| 11 |  | simp13 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑌  ⊆  𝐴 ) | 
						
							| 12 |  | simp2r | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑝  ∈  𝐴 ) | 
						
							| 13 |  | simp31 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑟  ∈  𝑋 ) | 
						
							| 14 |  | simp32 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑞  ∈  𝑌 ) | 
						
							| 15 | 11 14 | sseldd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑞  ∈  𝐴 ) | 
						
							| 16 | 10 13 | sseldd | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑟  ∈  𝐴 ) | 
						
							| 17 | 15 12 16 | 3jca | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  ( 𝑞  ∈  𝐴  ∧  𝑝  ∈  𝐴  ∧  𝑟  ∈  𝐴 ) ) | 
						
							| 18 |  | simp2l | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑋  ⊆  (  ⊥  ‘ 𝑌 ) ) | 
						
							| 19 | 1 2 3 4 5 6 7 8 | osumcllem4N | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑌  ⊆  𝐴  ∧  𝑋  ⊆  (  ⊥  ‘ 𝑌 ) )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌 ) )  →  𝑞  ≠  𝑟 ) | 
						
							| 20 | 9 11 18 13 14 19 | syl32anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑞  ≠  𝑟 ) | 
						
							| 21 | 9 17 20 | 3jca | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  ( 𝐾  ∈  HL  ∧  ( 𝑞  ∈  𝐴  ∧  𝑝  ∈  𝐴  ∧  𝑟  ∈  𝐴 )  ∧  𝑞  ≠  𝑟 ) ) | 
						
							| 22 |  | simp33 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) | 
						
							| 23 | 1 2 3 | hlatexch1 | ⊢ ( ( 𝐾  ∈  HL  ∧  ( 𝑞  ∈  𝐴  ∧  𝑝  ∈  𝐴  ∧  𝑟  ∈  𝐴 )  ∧  𝑞  ≠  𝑟 )  →  ( 𝑞  ≤  ( 𝑟  ∨  𝑝 )  →  𝑝  ≤  ( 𝑟  ∨  𝑞 ) ) ) | 
						
							| 24 | 21 22 23 | sylc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑝  ≤  ( 𝑟  ∨  𝑞 ) ) | 
						
							| 25 | 1 2 3 4 5 6 7 8 | osumcllem5N | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  𝑝  ∈  𝐴  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑝  ≤  ( 𝑟  ∨  𝑞 ) ) )  →  𝑝  ∈  ( 𝑋  +  𝑌 ) ) | 
						
							| 26 | 9 10 11 12 13 14 24 25 | syl313anc | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑋  ⊆  𝐴  ∧  𝑌  ⊆  𝐴 )  ∧  ( 𝑋  ⊆  (  ⊥  ‘ 𝑌 )  ∧  𝑝  ∈  𝐴 )  ∧  ( 𝑟  ∈  𝑋  ∧  𝑞  ∈  𝑌  ∧  𝑞  ≤  ( 𝑟  ∨  𝑝 ) ) )  →  𝑝  ∈  ( 𝑋  +  𝑌 ) ) |