| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝑆 )  =  ( Base ‘ 𝑆 )  | 
						
						
							| 2 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝑇 )  =  ( Base ‘ 𝑇 )  | 
						
						
							| 3 | 
							
								1 2
							 | 
							lmhmf | 
							⊢ ( 𝐹  ∈  ( 𝑆  LMHom  𝑇 )  →  𝐹 : ( Base ‘ 𝑆 ) ⟶ ( Base ‘ 𝑇 ) )  | 
						
						
							| 4 | 
							
								
							 | 
							frel | 
							⊢ ( 𝐹 : ( Base ‘ 𝑆 ) ⟶ ( Base ‘ 𝑇 )  →  Rel  𝐹 )  | 
						
						
							| 5 | 
							
								3 4
							 | 
							syl | 
							⊢ ( 𝐹  ∈  ( 𝑆  LMHom  𝑇 )  →  Rel  𝐹 )  | 
						
						
							| 6 | 
							
								
							 | 
							dfrel2 | 
							⊢ ( Rel  𝐹  ↔  ◡ ◡ 𝐹  =  𝐹 )  | 
						
						
							| 7 | 
							
								5 6
							 | 
							sylib | 
							⊢ ( 𝐹  ∈  ( 𝑆  LMHom  𝑇 )  →  ◡ ◡ 𝐹  =  𝐹 )  | 
						
						
							| 8 | 
							
								
							 | 
							id | 
							⊢ ( 𝐹  ∈  ( 𝑆  LMHom  𝑇 )  →  𝐹  ∈  ( 𝑆  LMHom  𝑇 ) )  | 
						
						
							| 9 | 
							
								7 8
							 | 
							eqeltrd | 
							⊢ ( 𝐹  ∈  ( 𝑆  LMHom  𝑇 )  →  ◡ ◡ 𝐹  ∈  ( 𝑆  LMHom  𝑇 ) )  | 
						
						
							| 10 | 
							
								9
							 | 
							anim1ci | 
							⊢ ( ( 𝐹  ∈  ( 𝑆  LMHom  𝑇 )  ∧  ◡ 𝐹  ∈  ( 𝑇  LMHom  𝑆 ) )  →  ( ◡ 𝐹  ∈  ( 𝑇  LMHom  𝑆 )  ∧  ◡ ◡ 𝐹  ∈  ( 𝑆  LMHom  𝑇 ) ) )  | 
						
						
							| 11 | 
							
								
							 | 
							islmim2 | 
							⊢ ( 𝐹  ∈  ( 𝑆  LMIso  𝑇 )  ↔  ( 𝐹  ∈  ( 𝑆  LMHom  𝑇 )  ∧  ◡ 𝐹  ∈  ( 𝑇  LMHom  𝑆 ) ) )  | 
						
						
							| 12 | 
							
								
							 | 
							islmim2 | 
							⊢ ( ◡ 𝐹  ∈  ( 𝑇  LMIso  𝑆 )  ↔  ( ◡ 𝐹  ∈  ( 𝑇  LMHom  𝑆 )  ∧  ◡ ◡ 𝐹  ∈  ( 𝑆  LMHom  𝑇 ) ) )  | 
						
						
							| 13 | 
							
								10 11 12
							 | 
							3imtr4i | 
							⊢ ( 𝐹  ∈  ( 𝑆  LMIso  𝑇 )  →  ◡ 𝐹  ∈  ( 𝑇  LMIso  𝑆 ) )  |