| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cdlemg4.l | ⊢  ≤   =  ( le ‘ 𝐾 ) | 
						
							| 2 |  | cdlemg4.a | ⊢ 𝐴  =  ( Atoms ‘ 𝐾 ) | 
						
							| 3 |  | cdlemg4.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 4 |  | cdlemg4.t | ⊢ 𝑇  =  ( ( LTrn ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 5 |  | cdlemg4.r | ⊢ 𝑅  =  ( ( trL ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 6 |  | cdlemg4.j | ⊢  ∨   =  ( join ‘ 𝐾 ) | 
						
							| 7 |  | cdlemg4b.v | ⊢ 𝑉  =  ( 𝑅 ‘ 𝐺 ) | 
						
							| 8 | 1 2 3 4 5 6 7 | cdlemg4b2 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  𝐺  ∈  𝑇 )  →  ( ( 𝐺 ‘ 𝑃 )  ∨  𝑉 )  =  ( 𝑃  ∨  ( 𝐺 ‘ 𝑃 ) ) ) | 
						
							| 9 | 1 2 3 4 5 6 7 | cdlemg4b1 | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  𝐺  ∈  𝑇 )  →  ( 𝑃  ∨  𝑉 )  =  ( 𝑃  ∨  ( 𝐺 ‘ 𝑃 ) ) ) | 
						
							| 10 | 8 9 | eqtr4d | ⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 )  ∧  𝐺  ∈  𝑇 )  →  ( ( 𝐺 ‘ 𝑃 )  ∨  𝑉 )  =  ( 𝑃  ∨  𝑉 ) ) |