| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mapdcnvord.h | ⊢ 𝐻  =  ( LHyp ‘ 𝐾 ) | 
						
							| 2 |  | mapdcnvord.m | ⊢ 𝑀  =  ( ( mapd ‘ 𝐾 ) ‘ 𝑊 ) | 
						
							| 3 |  | mapdcnvord.k | ⊢ ( 𝜑  →  ( 𝐾  ∈  HL  ∧  𝑊  ∈  𝐻 ) ) | 
						
							| 4 |  | mapdcnvord.x | ⊢ ( 𝜑  →  𝑋  ∈  ran  𝑀 ) | 
						
							| 5 |  | mapdcnvord.y | ⊢ ( 𝜑  →  𝑌  ∈  ran  𝑀 ) | 
						
							| 6 | 1 2 3 4 5 | mapdcnvordN | ⊢ ( 𝜑  →  ( ( ◡ 𝑀 ‘ 𝑋 )  ⊆  ( ◡ 𝑀 ‘ 𝑌 )  ↔  𝑋  ⊆  𝑌 ) ) | 
						
							| 7 | 1 2 3 5 4 | mapdcnvordN | ⊢ ( 𝜑  →  ( ( ◡ 𝑀 ‘ 𝑌 )  ⊆  ( ◡ 𝑀 ‘ 𝑋 )  ↔  𝑌  ⊆  𝑋 ) ) | 
						
							| 8 | 6 7 | anbi12d | ⊢ ( 𝜑  →  ( ( ( ◡ 𝑀 ‘ 𝑋 )  ⊆  ( ◡ 𝑀 ‘ 𝑌 )  ∧  ( ◡ 𝑀 ‘ 𝑌 )  ⊆  ( ◡ 𝑀 ‘ 𝑋 ) )  ↔  ( 𝑋  ⊆  𝑌  ∧  𝑌  ⊆  𝑋 ) ) ) | 
						
							| 9 |  | eqss | ⊢ ( ( ◡ 𝑀 ‘ 𝑋 )  =  ( ◡ 𝑀 ‘ 𝑌 )  ↔  ( ( ◡ 𝑀 ‘ 𝑋 )  ⊆  ( ◡ 𝑀 ‘ 𝑌 )  ∧  ( ◡ 𝑀 ‘ 𝑌 )  ⊆  ( ◡ 𝑀 ‘ 𝑋 ) ) ) | 
						
							| 10 |  | eqss | ⊢ ( 𝑋  =  𝑌  ↔  ( 𝑋  ⊆  𝑌  ∧  𝑌  ⊆  𝑋 ) ) | 
						
							| 11 | 8 9 10 | 3bitr4g | ⊢ ( 𝜑  →  ( ( ◡ 𝑀 ‘ 𝑋 )  =  ( ◡ 𝑀 ‘ 𝑌 )  ↔  𝑋  =  𝑌 ) ) |