| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							trljat.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							trljat.j | 
							⊢  ∨   =  ( join ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							trljat.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							trljat.h | 
							⊢ 𝐻  =  ( LHyp ‘ 𝐾 )  | 
						
						
							| 5 | 
							
								
							 | 
							trljat.t | 
							⊢ 𝑇  =  ( ( LTrn ‘ 𝐾 ) ‘ 𝑊 )  | 
						
						
							| 6 | 
							
								
							 | 
							trljat.r | 
							⊢ 𝑅  =  ( ( trL ‘ 𝐾 ) ‘ 𝑊 )  | 
						
						
							| 7 | 
							
								1 2 3 4 5 6
							 | 
							trljat1 | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 ) )  →  ( 𝑃  ∨  ( 𝑅 ‘ 𝐹 ) )  =  ( 𝑃  ∨  ( 𝐹 ‘ 𝑃 ) ) )  | 
						
						
							| 8 | 
							
								1 2 3 4 5 6
							 | 
							trljat2 | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 ) )  →  ( ( 𝐹 ‘ 𝑃 )  ∨  ( 𝑅 ‘ 𝐹 ) )  =  ( 𝑃  ∨  ( 𝐹 ‘ 𝑃 ) ) )  | 
						
						
							| 9 | 
							
								7 8
							 | 
							eqtr4d | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝑃  ∈  𝐴  ∧  ¬  𝑃  ≤  𝑊 ) )  →  ( 𝑃  ∨  ( 𝑅 ‘ 𝐹 ) )  =  ( ( 𝐹 ‘ 𝑃 )  ∨  ( 𝑅 ‘ 𝐹 ) ) )  |