| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ralxpmap.j | ⊢ ( 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  →  ( 𝜑  ↔  𝜓 ) ) | 
						
							| 2 |  | vex | ⊢ 𝑔  ∈  V | 
						
							| 3 |  | snex | ⊢ { 〈 𝐽 ,  𝑦 〉 }  ∈  V | 
						
							| 4 | 2 3 | unex | ⊢ ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  ∈  V | 
						
							| 5 |  | simpr | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) ) | 
						
							| 6 |  | elmapex | ⊢ ( 𝑓  ∈  ( 𝑆  ↑m  𝑇 )  →  ( 𝑆  ∈  V  ∧  𝑇  ∈  V ) ) | 
						
							| 7 | 6 | adantl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  ( 𝑆  ∈  V  ∧  𝑇  ∈  V ) ) | 
						
							| 8 |  | elmapg | ⊢ ( ( 𝑆  ∈  V  ∧  𝑇  ∈  V )  →  ( 𝑓  ∈  ( 𝑆  ↑m  𝑇 )  ↔  𝑓 : 𝑇 ⟶ 𝑆 ) ) | 
						
							| 9 | 7 8 | syl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  ( 𝑓  ∈  ( 𝑆  ↑m  𝑇 )  ↔  𝑓 : 𝑇 ⟶ 𝑆 ) ) | 
						
							| 10 | 5 9 | mpbid | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  𝑓 : 𝑇 ⟶ 𝑆 ) | 
						
							| 11 |  | simpl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  𝐽  ∈  𝑇 ) | 
						
							| 12 | 10 11 | ffvelcdmd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  ( 𝑓 ‘ 𝐽 )  ∈  𝑆 ) | 
						
							| 13 |  | difss | ⊢ ( 𝑇  ∖  { 𝐽 } )  ⊆  𝑇 | 
						
							| 14 |  | fssres | ⊢ ( ( 𝑓 : 𝑇 ⟶ 𝑆  ∧  ( 𝑇  ∖  { 𝐽 } )  ⊆  𝑇 )  →  ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) ) : ( 𝑇  ∖  { 𝐽 } ) ⟶ 𝑆 ) | 
						
							| 15 | 10 13 14 | sylancl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) ) : ( 𝑇  ∖  { 𝐽 } ) ⟶ 𝑆 ) | 
						
							| 16 | 6 | simpld | ⊢ ( 𝑓  ∈  ( 𝑆  ↑m  𝑇 )  →  𝑆  ∈  V ) | 
						
							| 17 | 16 | adantl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  𝑆  ∈  V ) | 
						
							| 18 | 7 | simprd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  𝑇  ∈  V ) | 
						
							| 19 | 18 | difexd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  ( 𝑇  ∖  { 𝐽 } )  ∈  V ) | 
						
							| 20 | 17 19 | elmapd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  ( ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) )  ↔  ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) ) : ( 𝑇  ∖  { 𝐽 } ) ⟶ 𝑆 ) ) | 
						
							| 21 | 15 20 | mpbird | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) | 
						
							| 22 | 10 | ffnd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  𝑓  Fn  𝑇 ) | 
						
							| 23 |  | fnsnsplit | ⊢ ( ( 𝑓  Fn  𝑇  ∧  𝐽  ∈  𝑇 )  →  𝑓  =  ( ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } ) ) | 
						
							| 24 | 22 11 23 | syl2anc | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  𝑓  =  ( ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } ) ) | 
						
							| 25 |  | opeq2 | ⊢ ( 𝑦  =  ( 𝑓 ‘ 𝐽 )  →  〈 𝐽 ,  𝑦 〉  =  〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 ) | 
						
							| 26 | 25 | sneqd | ⊢ ( 𝑦  =  ( 𝑓 ‘ 𝐽 )  →  { 〈 𝐽 ,  𝑦 〉 }  =  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } ) | 
						
							| 27 | 26 | uneq2d | ⊢ ( 𝑦  =  ( 𝑓 ‘ 𝐽 )  →  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  =  ( 𝑔  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } ) ) | 
						
							| 28 | 27 | eqeq2d | ⊢ ( 𝑦  =  ( 𝑓 ‘ 𝐽 )  →  ( 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  ↔  𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } ) ) ) | 
						
							| 29 |  | uneq1 | ⊢ ( 𝑔  =  ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  →  ( 𝑔  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } )  =  ( ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } ) ) | 
						
							| 30 | 29 | eqeq2d | ⊢ ( 𝑔  =  ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  →  ( 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } )  ↔  𝑓  =  ( ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } ) ) ) | 
						
							| 31 | 28 30 | rspc2ev | ⊢ ( ( ( 𝑓 ‘ 𝐽 )  ∈  𝑆  ∧  ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) )  ∧  𝑓  =  ( ( 𝑓  ↾  ( 𝑇  ∖  { 𝐽 } ) )  ∪  { 〈 𝐽 ,  ( 𝑓 ‘ 𝐽 ) 〉 } ) )  →  ∃ 𝑦  ∈  𝑆 ∃ 𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) ) | 
						
							| 32 | 12 21 24 31 | syl3anc | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) )  →  ∃ 𝑦  ∈  𝑆 ∃ 𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) ) | 
						
							| 33 | 32 | ex | ⊢ ( 𝐽  ∈  𝑇  →  ( 𝑓  ∈  ( 𝑆  ↑m  𝑇 )  →  ∃ 𝑦  ∈  𝑆 ∃ 𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) ) ) | 
						
							| 34 |  | elmapi | ⊢ ( 𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) )  →  𝑔 : ( 𝑇  ∖  { 𝐽 } ) ⟶ 𝑆 ) | 
						
							| 35 | 34 | ad2antll | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  𝑔 : ( 𝑇  ∖  { 𝐽 } ) ⟶ 𝑆 ) | 
						
							| 36 |  | f1osng | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑦  ∈  V )  →  { 〈 𝐽 ,  𝑦 〉 } : { 𝐽 } –1-1-onto→ { 𝑦 } ) | 
						
							| 37 |  | f1of | ⊢ ( { 〈 𝐽 ,  𝑦 〉 } : { 𝐽 } –1-1-onto→ { 𝑦 }  →  { 〈 𝐽 ,  𝑦 〉 } : { 𝐽 } ⟶ { 𝑦 } ) | 
						
							| 38 | 36 37 | syl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑦  ∈  V )  →  { 〈 𝐽 ,  𝑦 〉 } : { 𝐽 } ⟶ { 𝑦 } ) | 
						
							| 39 | 38 | elvd | ⊢ ( 𝐽  ∈  𝑇  →  { 〈 𝐽 ,  𝑦 〉 } : { 𝐽 } ⟶ { 𝑦 } ) | 
						
							| 40 | 39 | adantr | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  { 〈 𝐽 ,  𝑦 〉 } : { 𝐽 } ⟶ { 𝑦 } ) | 
						
							| 41 |  | disjdifr | ⊢ ( ( 𝑇  ∖  { 𝐽 } )  ∩  { 𝐽 } )  =  ∅ | 
						
							| 42 | 41 | a1i | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( ( 𝑇  ∖  { 𝐽 } )  ∩  { 𝐽 } )  =  ∅ ) | 
						
							| 43 |  | fun | ⊢ ( ( ( 𝑔 : ( 𝑇  ∖  { 𝐽 } ) ⟶ 𝑆  ∧  { 〈 𝐽 ,  𝑦 〉 } : { 𝐽 } ⟶ { 𝑦 } )  ∧  ( ( 𝑇  ∖  { 𝐽 } )  ∩  { 𝐽 } )  =  ∅ )  →  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) : ( ( 𝑇  ∖  { 𝐽 } )  ∪  { 𝐽 } ) ⟶ ( 𝑆  ∪  { 𝑦 } ) ) | 
						
							| 44 | 35 40 42 43 | syl21anc | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) : ( ( 𝑇  ∖  { 𝐽 } )  ∪  { 𝐽 } ) ⟶ ( 𝑆  ∪  { 𝑦 } ) ) | 
						
							| 45 |  | simpl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  𝐽  ∈  𝑇 ) | 
						
							| 46 | 45 | snssd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  { 𝐽 }  ⊆  𝑇 ) | 
						
							| 47 |  | undifr | ⊢ ( { 𝐽 }  ⊆  𝑇  ↔  ( ( 𝑇  ∖  { 𝐽 } )  ∪  { 𝐽 } )  =  𝑇 ) | 
						
							| 48 | 46 47 | sylib | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( ( 𝑇  ∖  { 𝐽 } )  ∪  { 𝐽 } )  =  𝑇 ) | 
						
							| 49 | 48 | feq2d | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) : ( ( 𝑇  ∖  { 𝐽 } )  ∪  { 𝐽 } ) ⟶ ( 𝑆  ∪  { 𝑦 } )  ↔  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) : 𝑇 ⟶ ( 𝑆  ∪  { 𝑦 } ) ) ) | 
						
							| 50 | 44 49 | mpbid | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) : 𝑇 ⟶ ( 𝑆  ∪  { 𝑦 } ) ) | 
						
							| 51 |  | ssidd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  𝑆  ⊆  𝑆 ) | 
						
							| 52 |  | snssi | ⊢ ( 𝑦  ∈  𝑆  →  { 𝑦 }  ⊆  𝑆 ) | 
						
							| 53 | 52 | ad2antrl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  { 𝑦 }  ⊆  𝑆 ) | 
						
							| 54 | 51 53 | unssd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑆  ∪  { 𝑦 } )  ⊆  𝑆 ) | 
						
							| 55 | 50 54 | fssd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) : 𝑇 ⟶ 𝑆 ) | 
						
							| 56 |  | elmapex | ⊢ ( 𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) )  →  ( 𝑆  ∈  V  ∧  ( 𝑇  ∖  { 𝐽 } )  ∈  V ) ) | 
						
							| 57 | 56 | ad2antll | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑆  ∈  V  ∧  ( 𝑇  ∖  { 𝐽 } )  ∈  V ) ) | 
						
							| 58 | 57 | simpld | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  𝑆  ∈  V ) | 
						
							| 59 |  | ssun1 | ⊢ 𝑇  ⊆  ( 𝑇  ∪  { 𝐽 } ) | 
						
							| 60 |  | undif1 | ⊢ ( ( 𝑇  ∖  { 𝐽 } )  ∪  { 𝐽 } )  =  ( 𝑇  ∪  { 𝐽 } ) | 
						
							| 61 | 57 | simprd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑇  ∖  { 𝐽 } )  ∈  V ) | 
						
							| 62 |  | snex | ⊢ { 𝐽 }  ∈  V | 
						
							| 63 |  | unexg | ⊢ ( ( ( 𝑇  ∖  { 𝐽 } )  ∈  V  ∧  { 𝐽 }  ∈  V )  →  ( ( 𝑇  ∖  { 𝐽 } )  ∪  { 𝐽 } )  ∈  V ) | 
						
							| 64 | 61 62 63 | sylancl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( ( 𝑇  ∖  { 𝐽 } )  ∪  { 𝐽 } )  ∈  V ) | 
						
							| 65 | 60 64 | eqeltrrid | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑇  ∪  { 𝐽 } )  ∈  V ) | 
						
							| 66 |  | ssexg | ⊢ ( ( 𝑇  ⊆  ( 𝑇  ∪  { 𝐽 } )  ∧  ( 𝑇  ∪  { 𝐽 } )  ∈  V )  →  𝑇  ∈  V ) | 
						
							| 67 | 59 65 66 | sylancr | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  𝑇  ∈  V ) | 
						
							| 68 | 58 67 | elmapd | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  ∈  ( 𝑆  ↑m  𝑇 )  ↔  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) : 𝑇 ⟶ 𝑆 ) ) | 
						
							| 69 | 55 68 | mpbird | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  ∈  ( 𝑆  ↑m  𝑇 ) ) | 
						
							| 70 |  | eleq1 | ⊢ ( 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  →  ( 𝑓  ∈  ( 𝑆  ↑m  𝑇 )  ↔  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  ∈  ( 𝑆  ↑m  𝑇 ) ) ) | 
						
							| 71 | 69 70 | syl5ibrcom | ⊢ ( ( 𝐽  ∈  𝑇  ∧  ( 𝑦  ∈  𝑆  ∧  𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) ) )  →  ( 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  →  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) ) ) | 
						
							| 72 | 71 | rexlimdvva | ⊢ ( 𝐽  ∈  𝑇  →  ( ∃ 𝑦  ∈  𝑆 ∃ 𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } )  →  𝑓  ∈  ( 𝑆  ↑m  𝑇 ) ) ) | 
						
							| 73 | 33 72 | impbid | ⊢ ( 𝐽  ∈  𝑇  →  ( 𝑓  ∈  ( 𝑆  ↑m  𝑇 )  ↔  ∃ 𝑦  ∈  𝑆 ∃ 𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) 𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) ) ) | 
						
							| 74 | 1 | adantl | ⊢ ( ( 𝐽  ∈  𝑇  ∧  𝑓  =  ( 𝑔  ∪  { 〈 𝐽 ,  𝑦 〉 } ) )  →  ( 𝜑  ↔  𝜓 ) ) | 
						
							| 75 | 4 73 74 | ralxpxfr2d | ⊢ ( 𝐽  ∈  𝑇  →  ( ∀ 𝑓  ∈  ( 𝑆  ↑m  𝑇 ) 𝜑  ↔  ∀ 𝑦  ∈  𝑆 ∀ 𝑔  ∈  ( 𝑆  ↑m  ( 𝑇  ∖  { 𝐽 } ) ) 𝜓 ) ) |