| Step | Hyp | Ref | Expression | 
						
							| 1 |  | neq0 | ⊢ ( ¬  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  =  ∅  ↔  ∃ 𝑦 𝑦  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) | 
						
							| 2 |  | vex | ⊢ 𝑦  ∈  V | 
						
							| 3 | 2 | elima | ⊢ ( 𝑦  ∈  ( 𝐻  “  𝐶 )  ↔  ∃ 𝑥  ∈  𝐶 𝑥 𝐻 𝑦 ) | 
						
							| 4 |  | ssel | ⊢ ( 𝐶  ⊆  𝐴  →  ( 𝑥  ∈  𝐶  →  𝑥  ∈  𝐴 ) ) | 
						
							| 5 |  | isof1o | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  𝐻 : 𝐴 –1-1-onto→ 𝐵 ) | 
						
							| 6 |  | f1ofn | ⊢ ( 𝐻 : 𝐴 –1-1-onto→ 𝐵  →  𝐻  Fn  𝐴 ) | 
						
							| 7 |  | fnbrfvb | ⊢ ( ( 𝐻  Fn  𝐴  ∧  𝑥  ∈  𝐴 )  →  ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ↔  𝑥 𝐻 𝑦 ) ) | 
						
							| 8 | 7 | ex | ⊢ ( 𝐻  Fn  𝐴  →  ( 𝑥  ∈  𝐴  →  ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ↔  𝑥 𝐻 𝑦 ) ) ) | 
						
							| 9 | 5 6 8 | 3syl | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  ( 𝑥  ∈  𝐴  →  ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ↔  𝑥 𝐻 𝑦 ) ) ) | 
						
							| 10 | 4 9 | syl9r | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  ( 𝐶  ⊆  𝐴  →  ( 𝑥  ∈  𝐶  →  ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ↔  𝑥 𝐻 𝑦 ) ) ) ) | 
						
							| 11 | 10 | imp31 | ⊢ ( ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  𝐶  ⊆  𝐴 )  ∧  𝑥  ∈  𝐶 )  →  ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ↔  𝑥 𝐻 𝑦 ) ) | 
						
							| 12 | 11 | rexbidva | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  𝐶  ⊆  𝐴 )  →  ( ∃ 𝑥  ∈  𝐶 ( 𝐻 ‘ 𝑥 )  =  𝑦  ↔  ∃ 𝑥  ∈  𝐶 𝑥 𝐻 𝑦 ) ) | 
						
							| 13 | 3 12 | bitr4id | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  𝐶  ⊆  𝐴 )  →  ( 𝑦  ∈  ( 𝐻  “  𝐶 )  ↔  ∃ 𝑥  ∈  𝐶 ( 𝐻 ‘ 𝑥 )  =  𝑦 ) ) | 
						
							| 14 |  | fvex | ⊢ ( 𝐻 ‘ 𝐷 )  ∈  V | 
						
							| 15 | 2 | eliniseg | ⊢ ( ( 𝐻 ‘ 𝐷 )  ∈  V  →  ( 𝑦  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } )  ↔  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) | 
						
							| 16 | 14 15 | mp1i | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  𝐶  ⊆  𝐴 )  →  ( 𝑦  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } )  ↔  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) | 
						
							| 17 | 13 16 | anbi12d | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  𝐶  ⊆  𝐴 )  →  ( ( 𝑦  ∈  ( 𝐻  “  𝐶 )  ∧  𝑦  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  ↔  ( ∃ 𝑥  ∈  𝐶 ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) ) | 
						
							| 18 |  | elin | ⊢ ( 𝑦  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  ↔  ( 𝑦  ∈  ( 𝐻  “  𝐶 )  ∧  𝑦  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) | 
						
							| 19 |  | r19.41v | ⊢ ( ∃ 𝑥  ∈  𝐶 ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) )  ↔  ( ∃ 𝑥  ∈  𝐶 ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) | 
						
							| 20 | 17 18 19 | 3bitr4g | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  𝐶  ⊆  𝐴 )  →  ( 𝑦  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  ↔  ∃ 𝑥  ∈  𝐶 ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) ) | 
						
							| 21 | 20 | adantrr | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑦  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  ↔  ∃ 𝑥  ∈  𝐶 ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) ) | 
						
							| 22 |  | breq1 | ⊢ ( ( 𝐻 ‘ 𝑥 )  =  𝑦  →  ( ( 𝐻 ‘ 𝑥 ) 𝑆 ( 𝐻 ‘ 𝐷 )  ↔  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) | 
						
							| 23 | 22 | biimpar | ⊢ ( ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) )  →  ( 𝐻 ‘ 𝑥 ) 𝑆 ( 𝐻 ‘ 𝐷 ) ) | 
						
							| 24 |  | vex | ⊢ 𝑥  ∈  V | 
						
							| 25 | 24 | eliniseg | ⊢ ( 𝐷  ∈  𝐴  →  ( 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  ↔  𝑥 𝑅 𝐷 ) ) | 
						
							| 26 | 25 | ad2antll | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝑥  ∈  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  ↔  𝑥 𝑅 𝐷 ) ) | 
						
							| 27 |  | isorel | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝑥  ∈  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥 𝑅 𝐷  ↔  ( 𝐻 ‘ 𝑥 ) 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) | 
						
							| 28 | 26 27 | bitrd | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝑥  ∈  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  ↔  ( 𝐻 ‘ 𝑥 ) 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) | 
						
							| 29 | 23 28 | imbitrrid | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝑥  ∈  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) )  →  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) | 
						
							| 30 | 29 | exp32 | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  ( 𝑥  ∈  𝐴  →  ( 𝐷  ∈  𝐴  →  ( ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) )  →  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) ) ) | 
						
							| 31 | 4 30 | syl9r | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  ( 𝐶  ⊆  𝐴  →  ( 𝑥  ∈  𝐶  →  ( 𝐷  ∈  𝐴  →  ( ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) )  →  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) ) ) ) | 
						
							| 32 | 31 | com34 | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  ( 𝐶  ⊆  𝐴  →  ( 𝐷  ∈  𝐴  →  ( 𝑥  ∈  𝐶  →  ( ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) )  →  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) ) ) ) | 
						
							| 33 | 32 | imp32 | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  𝐶  →  ( ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) )  →  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) ) | 
						
							| 34 | 33 | reximdvai | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ∃ 𝑥  ∈  𝐶 ( ( 𝐻 ‘ 𝑥 )  =  𝑦  ∧  𝑦 𝑆 ( 𝐻 ‘ 𝐷 ) )  →  ∃ 𝑥  ∈  𝐶 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) | 
						
							| 35 | 21 34 | sylbid | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑦  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  →  ∃ 𝑥  ∈  𝐶 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) | 
						
							| 36 |  | elin | ⊢ ( 𝑥  ∈  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  ↔  ( 𝑥  ∈  𝐶  ∧  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) | 
						
							| 37 | 36 | exbii | ⊢ ( ∃ 𝑥 𝑥  ∈  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  ↔  ∃ 𝑥 ( 𝑥  ∈  𝐶  ∧  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) | 
						
							| 38 |  | neq0 | ⊢ ( ¬  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  =  ∅  ↔  ∃ 𝑥 𝑥  ∈  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) ) ) | 
						
							| 39 |  | df-rex | ⊢ ( ∃ 𝑥  ∈  𝐶 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  ↔  ∃ 𝑥 ( 𝑥  ∈  𝐶  ∧  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) ) | 
						
							| 40 | 37 38 39 | 3bitr4i | ⊢ ( ¬  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  =  ∅  ↔  ∃ 𝑥  ∈  𝐶 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) ) | 
						
							| 41 | 35 40 | imbitrrdi | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑦  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  →  ¬  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  =  ∅ ) ) | 
						
							| 42 | 41 | exlimdv | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ∃ 𝑦 𝑦  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  →  ¬  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  =  ∅ ) ) | 
						
							| 43 | 1 42 | biimtrid | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ¬  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  =  ∅  →  ¬  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  =  ∅ ) ) | 
						
							| 44 | 43 | con4d | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  =  ∅  →  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  =  ∅ ) ) | 
						
							| 45 | 5 6 | syl | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  𝐻  Fn  𝐴 ) | 
						
							| 46 |  | fnfvima | ⊢ ( ( 𝐻  Fn  𝐴  ∧  𝐶  ⊆  𝐴  ∧  𝑥  ∈  𝐶 )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( 𝐻  “  𝐶 ) ) | 
						
							| 47 | 46 | 3expia | ⊢ ( ( 𝐻  Fn  𝐴  ∧  𝐶  ⊆  𝐴 )  →  ( 𝑥  ∈  𝐶  →  ( 𝐻 ‘ 𝑥 )  ∈  ( 𝐻  “  𝐶 ) ) ) | 
						
							| 48 | 47 | adantrr | ⊢ ( ( 𝐻  Fn  𝐴  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  𝐶  →  ( 𝐻 ‘ 𝑥 )  ∈  ( 𝐻  “  𝐶 ) ) ) | 
						
							| 49 | 45 48 | sylan | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  𝐶  →  ( 𝐻 ‘ 𝑥 )  ∈  ( 𝐻  “  𝐶 ) ) ) | 
						
							| 50 | 49 | adantrd | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ( 𝑥  ∈  𝐶  ∧  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( 𝐻  “  𝐶 ) ) ) | 
						
							| 51 | 27 | biimpd | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝑥  ∈  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥 𝑅 𝐷  →  ( 𝐻 ‘ 𝑥 ) 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) | 
						
							| 52 |  | fvex | ⊢ ( 𝐻 ‘ 𝑥 )  ∈  V | 
						
							| 53 | 52 | eliniseg | ⊢ ( ( 𝐻 ‘ 𝐷 )  ∈  V  →  ( ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } )  ↔  ( 𝐻 ‘ 𝑥 ) 𝑆 ( 𝐻 ‘ 𝐷 ) ) ) | 
						
							| 54 | 14 53 | ax-mp | ⊢ ( ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } )  ↔  ( 𝐻 ‘ 𝑥 ) 𝑆 ( 𝐻 ‘ 𝐷 ) ) | 
						
							| 55 | 51 54 | imbitrrdi | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝑥  ∈  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥 𝑅 𝐷  →  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) | 
						
							| 56 | 26 55 | sylbid | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝑥  ∈  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) | 
						
							| 57 | 56 | exp32 | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  ( 𝑥  ∈  𝐴  →  ( 𝐷  ∈  𝐴  →  ( 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) ) ) | 
						
							| 58 | 4 57 | syl9r | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  ( 𝐶  ⊆  𝐴  →  ( 𝑥  ∈  𝐶  →  ( 𝐷  ∈  𝐴  →  ( 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) ) ) ) | 
						
							| 59 | 58 | com34 | ⊢ ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  →  ( 𝐶  ⊆  𝐴  →  ( 𝐷  ∈  𝐴  →  ( 𝑥  ∈  𝐶  →  ( 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) ) ) ) | 
						
							| 60 | 59 | imp32 | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  𝐶  →  ( 𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) ) | 
						
							| 61 | 60 | impd | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ( 𝑥  ∈  𝐶  ∧  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) | 
						
							| 62 | 50 61 | jcad | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ( 𝑥  ∈  𝐶  ∧  𝑥  ∈  ( ◡ 𝑅  “  { 𝐷 } ) )  →  ( ( 𝐻 ‘ 𝑥 )  ∈  ( 𝐻  “  𝐶 )  ∧  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) ) | 
						
							| 63 |  | elin | ⊢ ( ( 𝐻 ‘ 𝑥 )  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  ↔  ( ( 𝐻 ‘ 𝑥 )  ∈  ( 𝐻  “  𝐶 )  ∧  ( 𝐻 ‘ 𝑥 )  ∈  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) | 
						
							| 64 | 62 36 63 | 3imtr4g | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  →  ( 𝐻 ‘ 𝑥 )  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) ) ) ) | 
						
							| 65 |  | n0i | ⊢ ( ( 𝐻 ‘ 𝑥 )  ∈  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  →  ¬  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  =  ∅ ) | 
						
							| 66 | 64 65 | syl6 | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( 𝑥  ∈  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  →  ¬  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  =  ∅ ) ) | 
						
							| 67 | 66 | exlimdv | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ∃ 𝑥 𝑥  ∈  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  →  ¬  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  =  ∅ ) ) | 
						
							| 68 | 38 67 | biimtrid | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ¬  ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  =  ∅  →  ¬  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  =  ∅ ) ) | 
						
							| 69 | 44 68 | impcon4bid | ⊢ ( ( 𝐻  Isom  𝑅 ,  𝑆 ( 𝐴 ,  𝐵 )  ∧  ( 𝐶  ⊆  𝐴  ∧  𝐷  ∈  𝐴 ) )  →  ( ( 𝐶  ∩  ( ◡ 𝑅  “  { 𝐷 } ) )  =  ∅  ↔  ( ( 𝐻  “  𝐶 )  ∩  ( ◡ 𝑆  “  { ( 𝐻 ‘ 𝐷 ) } ) )  =  ∅ ) ) |