| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ltrncvr.b | ⊢ 𝐵  =  ( Base ‘ 𝐾 ) | 
						
							| 2 |  | ltrncvr.c | ⊢ 𝐶  =  (  ⋖  ‘ 𝐾 ) | 
						
							| 3 |  | ltrncvr.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 4 |  | ltrncvr.t | ⊢ 𝑇  =  ( ( LTrn ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 5 |  | simp1l | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 ) )  →  𝐾  ∈  𝑉 ) | 
						
							| 6 |  | eqid | ⊢ ( LAut ‘ 𝐾 )  =  ( LAut ‘ 𝐾 ) | 
						
							| 7 | 3 6 4 | ltrnlaut | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇 )  →  𝐹  ∈  ( LAut ‘ 𝐾 ) ) | 
						
							| 8 | 7 | 3adant3 | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 ) )  →  𝐹  ∈  ( LAut ‘ 𝐾 ) ) | 
						
							| 9 |  | simp3l | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 10 |  | simp3r | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 ) )  →  𝑌  ∈  𝐵 ) | 
						
							| 11 | 1 2 6 | lautcvr | ⊢ ( ( 𝐾  ∈  𝑉  ∧  ( 𝐹  ∈  ( LAut ‘ 𝐾 )  ∧  𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 ) )  →  ( 𝑋 𝐶 𝑌  ↔  ( 𝐹 ‘ 𝑋 ) 𝐶 ( 𝐹 ‘ 𝑌 ) ) ) | 
						
							| 12 | 5 8 9 10 11 | syl13anc | ⊢ ( ( ( 𝐾  ∈  𝑉  ∧  𝑊  ∈  𝐻 )  ∧  𝐹  ∈  𝑇  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 ) )  →  ( 𝑋 𝐶 𝑌  ↔  ( 𝐹 ‘ 𝑋 ) 𝐶 ( 𝐹 ‘ 𝑌 ) ) ) |