| Step | Hyp | Ref | Expression | 
						
							| 1 |  | shftfval.1 | ⊢ 𝐹  ∈  V | 
						
							| 2 | 1 | shftfval | ⊢ ( 𝐴  ∈  ℂ  →  ( 𝐹  shift  𝐴 )  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ℂ  ∧  ( 𝑥  −  𝐴 ) 𝐹 𝑦 ) } ) | 
						
							| 3 | 2 | breqd | ⊢ ( 𝐴  ∈  ℂ  →  ( 𝐵 ( 𝐹  shift  𝐴 ) 𝑧  ↔  𝐵 { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ℂ  ∧  ( 𝑥  −  𝐴 ) 𝐹 𝑦 ) } 𝑧 ) ) | 
						
							| 4 |  | eleq1 | ⊢ ( 𝑥  =  𝐵  →  ( 𝑥  ∈  ℂ  ↔  𝐵  ∈  ℂ ) ) | 
						
							| 5 |  | oveq1 | ⊢ ( 𝑥  =  𝐵  →  ( 𝑥  −  𝐴 )  =  ( 𝐵  −  𝐴 ) ) | 
						
							| 6 | 5 | breq1d | ⊢ ( 𝑥  =  𝐵  →  ( ( 𝑥  −  𝐴 ) 𝐹 𝑦  ↔  ( 𝐵  −  𝐴 ) 𝐹 𝑦 ) ) | 
						
							| 7 | 4 6 | anbi12d | ⊢ ( 𝑥  =  𝐵  →  ( ( 𝑥  ∈  ℂ  ∧  ( 𝑥  −  𝐴 ) 𝐹 𝑦 )  ↔  ( 𝐵  ∈  ℂ  ∧  ( 𝐵  −  𝐴 ) 𝐹 𝑦 ) ) ) | 
						
							| 8 |  | breq2 | ⊢ ( 𝑦  =  𝑧  →  ( ( 𝐵  −  𝐴 ) 𝐹 𝑦  ↔  ( 𝐵  −  𝐴 ) 𝐹 𝑧 ) ) | 
						
							| 9 | 8 | anbi2d | ⊢ ( 𝑦  =  𝑧  →  ( ( 𝐵  ∈  ℂ  ∧  ( 𝐵  −  𝐴 ) 𝐹 𝑦 )  ↔  ( 𝐵  ∈  ℂ  ∧  ( 𝐵  −  𝐴 ) 𝐹 𝑧 ) ) ) | 
						
							| 10 |  | eqid | ⊢ { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ℂ  ∧  ( 𝑥  −  𝐴 ) 𝐹 𝑦 ) }  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ℂ  ∧  ( 𝑥  −  𝐴 ) 𝐹 𝑦 ) } | 
						
							| 11 | 7 9 10 | brabg | ⊢ ( ( 𝐵  ∈  ℂ  ∧  𝑧  ∈  V )  →  ( 𝐵 { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ℂ  ∧  ( 𝑥  −  𝐴 ) 𝐹 𝑦 ) } 𝑧  ↔  ( 𝐵  ∈  ℂ  ∧  ( 𝐵  −  𝐴 ) 𝐹 𝑧 ) ) ) | 
						
							| 12 | 11 | elvd | ⊢ ( 𝐵  ∈  ℂ  →  ( 𝐵 { 〈 𝑥 ,  𝑦 〉  ∣  ( 𝑥  ∈  ℂ  ∧  ( 𝑥  −  𝐴 ) 𝐹 𝑦 ) } 𝑧  ↔  ( 𝐵  ∈  ℂ  ∧  ( 𝐵  −  𝐴 ) 𝐹 𝑧 ) ) ) | 
						
							| 13 | 3 12 | sylan9bb | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ )  →  ( 𝐵 ( 𝐹  shift  𝐴 ) 𝑧  ↔  ( 𝐵  ∈  ℂ  ∧  ( 𝐵  −  𝐴 ) 𝐹 𝑧 ) ) ) | 
						
							| 14 |  | ibar | ⊢ ( 𝐵  ∈  ℂ  →  ( ( 𝐵  −  𝐴 ) 𝐹 𝑧  ↔  ( 𝐵  ∈  ℂ  ∧  ( 𝐵  −  𝐴 ) 𝐹 𝑧 ) ) ) | 
						
							| 15 | 14 | adantl | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ )  →  ( ( 𝐵  −  𝐴 ) 𝐹 𝑧  ↔  ( 𝐵  ∈  ℂ  ∧  ( 𝐵  −  𝐴 ) 𝐹 𝑧 ) ) ) | 
						
							| 16 | 13 15 | bitr4d | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ )  →  ( 𝐵 ( 𝐹  shift  𝐴 ) 𝑧  ↔  ( 𝐵  −  𝐴 ) 𝐹 𝑧 ) ) | 
						
							| 17 | 16 | abbidv | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ )  →  { 𝑧  ∣  𝐵 ( 𝐹  shift  𝐴 ) 𝑧 }  =  { 𝑧  ∣  ( 𝐵  −  𝐴 ) 𝐹 𝑧 } ) | 
						
							| 18 |  | imasng | ⊢ ( 𝐵  ∈  ℂ  →  ( ( 𝐹  shift  𝐴 )  “  { 𝐵 } )  =  { 𝑧  ∣  𝐵 ( 𝐹  shift  𝐴 ) 𝑧 } ) | 
						
							| 19 | 18 | adantl | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ )  →  ( ( 𝐹  shift  𝐴 )  “  { 𝐵 } )  =  { 𝑧  ∣  𝐵 ( 𝐹  shift  𝐴 ) 𝑧 } ) | 
						
							| 20 |  | ovex | ⊢ ( 𝐵  −  𝐴 )  ∈  V | 
						
							| 21 |  | imasng | ⊢ ( ( 𝐵  −  𝐴 )  ∈  V  →  ( 𝐹  “  { ( 𝐵  −  𝐴 ) } )  =  { 𝑧  ∣  ( 𝐵  −  𝐴 ) 𝐹 𝑧 } ) | 
						
							| 22 | 20 21 | mp1i | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ )  →  ( 𝐹  “  { ( 𝐵  −  𝐴 ) } )  =  { 𝑧  ∣  ( 𝐵  −  𝐴 ) 𝐹 𝑧 } ) | 
						
							| 23 | 17 19 22 | 3eqtr4d | ⊢ ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ )  →  ( ( 𝐹  shift  𝐴 )  “  { 𝐵 } )  =  ( 𝐹  “  { ( 𝐵  −  𝐴 ) } ) ) |