| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rngop.1 | ⊢ 𝐹  =  ( 𝑥  ∈  𝐴 ,  𝑦  ∈  𝐵  ↦  𝐶 ) | 
						
							| 2 |  | eqeq1 | ⊢ ( 𝑧  =  𝐷  →  ( 𝑧  =  𝐶  ↔  𝐷  =  𝐶 ) ) | 
						
							| 3 | 2 | anbi1d | ⊢ ( 𝑧  =  𝐷  →  ( ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 )  ↔  ( 𝐷  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) | 
						
							| 4 | 3 | anbi2d | ⊢ ( 𝑧  =  𝐷  →  ( ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) )  ↔  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝐷  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) ) | 
						
							| 5 | 4 | 2exbidv | ⊢ ( 𝑧  =  𝐷  →  ( ∃ 𝑥 ∃ 𝑦 ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) )  ↔  ∃ 𝑥 ∃ 𝑦 ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝐷  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) ) | 
						
							| 6 |  | an12 | ⊢ ( ( 𝑝  ∈  𝑅  ∧  ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) )  ↔  ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( 𝑝  ∈  𝑅  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) ) ) | 
						
							| 7 |  | an12 | ⊢ ( ( 𝑝  ∈  𝑅  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) )  ↔  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝑅  ∧  𝑧  =  𝐶 ) ) ) | 
						
							| 8 |  | ancom | ⊢ ( ( 𝑧  =  𝐶  ∧  𝑝  ∈  𝑅 )  ↔  ( 𝑝  ∈  𝑅  ∧  𝑧  =  𝐶 ) ) | 
						
							| 9 |  | eleq1 | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( 𝑝  ∈  𝑅  ↔  〈 𝑥 ,  𝑦 〉  ∈  𝑅 ) ) | 
						
							| 10 |  | df-br | ⊢ ( 𝑥 𝑅 𝑦  ↔  〈 𝑥 ,  𝑦 〉  ∈  𝑅 ) | 
						
							| 11 | 9 10 | bitr4di | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( 𝑝  ∈  𝑅  ↔  𝑥 𝑅 𝑦 ) ) | 
						
							| 12 | 11 | anbi2d | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( ( 𝑧  =  𝐶  ∧  𝑝  ∈  𝑅 )  ↔  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) | 
						
							| 13 | 8 12 | bitr3id | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( ( 𝑝  ∈  𝑅  ∧  𝑧  =  𝐶 )  ↔  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) | 
						
							| 14 | 13 | anbi2d | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑝  ∈  𝑅  ∧  𝑧  =  𝐶 ) )  ↔  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) ) | 
						
							| 15 | 7 14 | bitrid | ⊢ ( 𝑝  =  〈 𝑥 ,  𝑦 〉  →  ( ( 𝑝  ∈  𝑅  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) )  ↔  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) ) | 
						
							| 16 | 15 | pm5.32i | ⊢ ( ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( 𝑝  ∈  𝑅  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) )  ↔  ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) ) | 
						
							| 17 | 6 16 | bitri | ⊢ ( ( 𝑝  ∈  𝑅  ∧  ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) )  ↔  ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) ) | 
						
							| 18 | 17 | 2exbii | ⊢ ( ∃ 𝑥 ∃ 𝑦 ( 𝑝  ∈  𝑅  ∧  ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) )  ↔  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) ) | 
						
							| 19 |  | 19.42vv | ⊢ ( ∃ 𝑥 ∃ 𝑦 ( 𝑝  ∈  𝑅  ∧  ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) )  ↔  ( 𝑝  ∈  𝑅  ∧  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) ) ) | 
						
							| 20 | 18 19 | bitr3i | ⊢ ( ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) )  ↔  ( 𝑝  ∈  𝑅  ∧  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) ) ) | 
						
							| 21 | 20 | opabbii | ⊢ { 〈 𝑝 ,  𝑧 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) }  =  { 〈 𝑝 ,  𝑧 〉  ∣  ( 𝑝  ∈  𝑅  ∧  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) ) } | 
						
							| 22 |  | dfoprab2 | ⊢ { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑧 〉  ∣  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) }  =  { 〈 𝑝 ,  𝑧 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) } | 
						
							| 23 |  | df-mpo | ⊢ ( 𝑥  ∈  𝐴 ,  𝑦  ∈  𝐵  ↦  𝐶 )  =  { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑧 〉  ∣  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) } | 
						
							| 24 |  | dfoprab2 | ⊢ { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑧 〉  ∣  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) }  =  { 〈 𝑝 ,  𝑧 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) } | 
						
							| 25 | 1 23 24 | 3eqtri | ⊢ 𝐹  =  { 〈 𝑝 ,  𝑧 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) } | 
						
							| 26 | 25 | reseq1i | ⊢ ( 𝐹  ↾  𝑅 )  =  ( { 〈 𝑝 ,  𝑧 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) }  ↾  𝑅 ) | 
						
							| 27 |  | resopab | ⊢ ( { 〈 𝑝 ,  𝑧 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) }  ↾  𝑅 )  =  { 〈 𝑝 ,  𝑧 〉  ∣  ( 𝑝  ∈  𝑅  ∧  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) ) } | 
						
							| 28 | 26 27 | eqtri | ⊢ ( 𝐹  ↾  𝑅 )  =  { 〈 𝑝 ,  𝑧 〉  ∣  ( 𝑝  ∈  𝑅  ∧  ∃ 𝑥 ∃ 𝑦 ( 𝑝  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  𝑧  =  𝐶 ) ) ) } | 
						
							| 29 | 21 22 28 | 3eqtr4ri | ⊢ ( 𝐹  ↾  𝑅 )  =  { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑧 〉  ∣  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) } | 
						
							| 30 | 29 | rneqi | ⊢ ran  ( 𝐹  ↾  𝑅 )  =  ran  { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑧 〉  ∣  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) } | 
						
							| 31 |  | rnoprab | ⊢ ran  { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑧 〉  ∣  ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) }  =  { 𝑧  ∣  ∃ 𝑥 ∃ 𝑦 ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) } | 
						
							| 32 | 30 31 | eqtri | ⊢ ran  ( 𝐹  ↾  𝑅 )  =  { 𝑧  ∣  ∃ 𝑥 ∃ 𝑦 ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝑧  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) } | 
						
							| 33 | 5 32 | elab2g | ⊢ ( 𝐷  ∈  𝑉  →  ( 𝐷  ∈  ran  ( 𝐹  ↾  𝑅 )  ↔  ∃ 𝑥 ∃ 𝑦 ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝐷  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) ) | 
						
							| 34 |  | r2ex | ⊢ ( ∃ 𝑥  ∈  𝐴 ∃ 𝑦  ∈  𝐵 ( 𝐷  =  𝐶  ∧  𝑥 𝑅 𝑦 )  ↔  ∃ 𝑥 ∃ 𝑦 ( ( 𝑥  ∈  𝐴  ∧  𝑦  ∈  𝐵 )  ∧  ( 𝐷  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) | 
						
							| 35 | 33 34 | bitr4di | ⊢ ( 𝐷  ∈  𝑉  →  ( 𝐷  ∈  ran  ( 𝐹  ↾  𝑅 )  ↔  ∃ 𝑥  ∈  𝐴 ∃ 𝑦  ∈  𝐵 ( 𝐷  =  𝐶  ∧  𝑥 𝑅 𝑦 ) ) ) |