| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							ltrnel.l | 
							⊢  ≤   =  ( le ‘ 𝐾 )  | 
						
						
							| 2 | 
							
								
							 | 
							ltrnel.a | 
							⊢ 𝐴  =  ( Atoms ‘ 𝐾 )  | 
						
						
							| 3 | 
							
								
							 | 
							ltrnel.h | 
							⊢ 𝐻  =  ( LHyp ‘ 𝐾 )  | 
						
						
							| 4 | 
							
								
							 | 
							ltrnel.t | 
							⊢ 𝑇  =  ( ( LTrn ‘ 𝐾 ) ‘ 𝑊 )  | 
						
						
							| 5 | 
							
								
							 | 
							simp1 | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  𝑇  ∧  𝐺  ∈  𝑇 )  ∧  𝑃  ∈  𝐴 )  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) )  | 
						
						
							| 6 | 
							
								
							 | 
							simp2l | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  𝑇  ∧  𝐺  ∈  𝑇 )  ∧  𝑃  ∈  𝐴 )  →  𝐹  ∈  𝑇 )  | 
						
						
							| 7 | 
							
								1 2 3 4
							 | 
							ltrnat | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  𝐺  ∈  𝑇  ∧  𝑃  ∈  𝐴 )  →  ( 𝐺 ‘ 𝑃 )  ∈  𝐴 )  | 
						
						
							| 8 | 
							
								7
							 | 
							3adant2l | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  𝑇  ∧  𝐺  ∈  𝑇 )  ∧  𝑃  ∈  𝐴 )  →  ( 𝐺 ‘ 𝑃 )  ∈  𝐴 )  | 
						
						
							| 9 | 
							
								1 2 3 4
							 | 
							ltrnat | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝐺 ‘ 𝑃 )  ∈  𝐴 )  →  ( 𝐹 ‘ ( 𝐺 ‘ 𝑃 ) )  ∈  𝐴 )  | 
						
						
							| 10 | 
							
								5 6 8 9
							 | 
							syl3anc | 
							⊢ ( ( ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 )  ∧  ( 𝐹  ∈  𝑇  ∧  𝐺  ∈  𝑇 )  ∧  𝑃  ∈  𝐴 )  →  ( 𝐹 ‘ ( 𝐺 ‘ 𝑃 ) )  ∈  𝐴 )  |