| Step | Hyp | Ref | Expression | 
						
							| 1 |  | resco | ⊢ ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  𝑅 )  ↾  𝐴 )  =  ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  ( 𝑅  ↾  𝐴 ) ) | 
						
							| 2 |  | resco | ⊢ ( ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  𝑆 )  ↾  𝐴 )  =  ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  ( 𝑆  ↾  𝐴 ) ) | 
						
							| 3 | 1 2 | ineq12i | ⊢ ( ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  𝑅 )  ↾  𝐴 )  ∩  ( ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  𝑆 )  ↾  𝐴 ) )  =  ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  ( 𝑅  ↾  𝐴 ) )  ∩  ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  ( 𝑆  ↾  𝐴 ) ) ) | 
						
							| 4 |  | df-xrn | ⊢ ( 𝑅  ⋉  𝑆 )  =  ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  𝑅 )  ∩  ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  𝑆 ) ) | 
						
							| 5 | 4 | reseq1i | ⊢ ( ( 𝑅  ⋉  𝑆 )  ↾  𝐴 )  =  ( ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  𝑅 )  ∩  ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  𝑆 ) )  ↾  𝐴 ) | 
						
							| 6 |  | resindir | ⊢ ( ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  𝑅 )  ∩  ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  𝑆 ) )  ↾  𝐴 )  =  ( ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  𝑅 )  ↾  𝐴 )  ∩  ( ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  𝑆 )  ↾  𝐴 ) ) | 
						
							| 7 | 5 6 | eqtri | ⊢ ( ( 𝑅  ⋉  𝑆 )  ↾  𝐴 )  =  ( ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  𝑅 )  ↾  𝐴 )  ∩  ( ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  𝑆 )  ↾  𝐴 ) ) | 
						
							| 8 |  | df-xrn | ⊢ ( ( 𝑅  ↾  𝐴 )  ⋉  ( 𝑆  ↾  𝐴 ) )  =  ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  ( 𝑅  ↾  𝐴 ) )  ∩  ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  ( 𝑆  ↾  𝐴 ) ) ) | 
						
							| 9 | 3 7 8 | 3eqtr4i | ⊢ ( ( 𝑅  ⋉  𝑆 )  ↾  𝐴 )  =  ( ( 𝑅  ↾  𝐴 )  ⋉  ( 𝑆  ↾  𝐴 ) ) |