| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ackbijnn.1 | ⊢ 𝐹  =  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  Σ 𝑦  ∈  𝑥 ( 2 ↑ 𝑦 ) ) | 
						
							| 2 |  | hashgval2 | ⊢ ( ♯  ↾  ω )  =  ( rec ( ( 𝑥  ∈  V  ↦  ( 𝑥  +  1 ) ) ,  0 )  ↾  ω ) | 
						
							| 3 | 2 | hashgf1o | ⊢ ( ♯  ↾  ω ) : ω –1-1-onto→ ℕ0 | 
						
							| 4 |  | sneq | ⊢ ( 𝑤  =  𝑦  →  { 𝑤 }  =  { 𝑦 } ) | 
						
							| 5 |  | pweq | ⊢ ( 𝑤  =  𝑦  →  𝒫  𝑤  =  𝒫  𝑦 ) | 
						
							| 6 | 4 5 | xpeq12d | ⊢ ( 𝑤  =  𝑦  →  ( { 𝑤 }  ×  𝒫  𝑤 )  =  ( { 𝑦 }  ×  𝒫  𝑦 ) ) | 
						
							| 7 | 6 | cbviunv | ⊢ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 )  =  ∪  𝑦  ∈  𝑧 ( { 𝑦 }  ×  𝒫  𝑦 ) | 
						
							| 8 |  | iuneq1 | ⊢ ( 𝑧  =  𝑥  →  ∪  𝑦  ∈  𝑧 ( { 𝑦 }  ×  𝒫  𝑦 )  =  ∪  𝑦  ∈  𝑥 ( { 𝑦 }  ×  𝒫  𝑦 ) ) | 
						
							| 9 | 7 8 | eqtrid | ⊢ ( 𝑧  =  𝑥  →  ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 )  =  ∪  𝑦  ∈  𝑥 ( { 𝑦 }  ×  𝒫  𝑦 ) ) | 
						
							| 10 | 9 | fveq2d | ⊢ ( 𝑧  =  𝑥  →  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) )  =  ( card ‘ ∪  𝑦  ∈  𝑥 ( { 𝑦 }  ×  𝒫  𝑦 ) ) ) | 
						
							| 11 | 10 | cbvmptv | ⊢ ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  =  ( 𝑥  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑦  ∈  𝑥 ( { 𝑦 }  ×  𝒫  𝑦 ) ) ) | 
						
							| 12 | 11 | ackbij1 | ⊢ ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) : ( 𝒫  ω  ∩  Fin ) –1-1-onto→ ω | 
						
							| 13 |  | f1ocnv | ⊢ ( ( ♯  ↾  ω ) : ω –1-1-onto→ ℕ0  →  ◡ ( ♯  ↾  ω ) : ℕ0 –1-1-onto→ ω ) | 
						
							| 14 | 3 13 | ax-mp | ⊢ ◡ ( ♯  ↾  ω ) : ℕ0 –1-1-onto→ ω | 
						
							| 15 |  | f1opwfi | ⊢ ( ◡ ( ♯  ↾  ω ) : ℕ0 –1-1-onto→ ω  →  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ( 𝒫  ω  ∩  Fin ) ) | 
						
							| 16 | 14 15 | ax-mp | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ( 𝒫  ω  ∩  Fin ) | 
						
							| 17 |  | f1oco | ⊢ ( ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) : ( 𝒫  ω  ∩  Fin ) –1-1-onto→ ω  ∧  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ( 𝒫  ω  ∩  Fin ) )  →  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ω ) | 
						
							| 18 | 12 16 17 | mp2an | ⊢ ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ω | 
						
							| 19 |  | f1oco | ⊢ ( ( ( ♯  ↾  ω ) : ω –1-1-onto→ ℕ0  ∧  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ω )  →  ( ( ♯  ↾  ω )  ∘  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ℕ0 ) | 
						
							| 20 | 3 18 19 | mp2an | ⊢ ( ( ♯  ↾  ω )  ∘  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ℕ0 | 
						
							| 21 |  | inss2 | ⊢ ( 𝒫  ω  ∩  Fin )  ⊆  Fin | 
						
							| 22 |  | f1of | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ( 𝒫  ω  ∩  Fin )  →  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) : ( 𝒫  ℕ0  ∩  Fin ) ⟶ ( 𝒫  ω  ∩  Fin ) ) | 
						
							| 23 | 16 22 | ax-mp | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) : ( 𝒫  ℕ0  ∩  Fin ) ⟶ ( 𝒫  ω  ∩  Fin ) | 
						
							| 24 |  | eqid | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) )  =  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) | 
						
							| 25 | 24 | fmpt | ⊢ ( ∀ 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin ) ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ∈  ( 𝒫  ω  ∩  Fin )  ↔  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) : ( 𝒫  ℕ0  ∩  Fin ) ⟶ ( 𝒫  ω  ∩  Fin ) ) | 
						
							| 26 | 23 25 | mpbir | ⊢ ∀ 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin ) ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ∈  ( 𝒫  ω  ∩  Fin ) | 
						
							| 27 | 26 | rspec | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ∈  ( 𝒫  ω  ∩  Fin ) ) | 
						
							| 28 | 21 27 | sselid | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ∈  Fin ) | 
						
							| 29 |  | snfi | ⊢ { 𝑤 }  ∈  Fin | 
						
							| 30 |  | cnvimass | ⊢ ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ⊆  dom  ( ♯  ↾  ω ) | 
						
							| 31 |  | dmhashres | ⊢ dom  ( ♯  ↾  ω )  =  ω | 
						
							| 32 | 30 31 | sseqtri | ⊢ ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ⊆  ω | 
						
							| 33 |  | onfin2 | ⊢ ω  =  ( On  ∩  Fin ) | 
						
							| 34 |  | inss2 | ⊢ ( On  ∩  Fin )  ⊆  Fin | 
						
							| 35 | 33 34 | eqsstri | ⊢ ω  ⊆  Fin | 
						
							| 36 | 32 35 | sstri | ⊢ ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ⊆  Fin | 
						
							| 37 |  | simpr | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) )  →  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) | 
						
							| 38 | 36 37 | sselid | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) )  →  𝑤  ∈  Fin ) | 
						
							| 39 |  | pwfi | ⊢ ( 𝑤  ∈  Fin  ↔  𝒫  𝑤  ∈  Fin ) | 
						
							| 40 | 38 39 | sylib | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) )  →  𝒫  𝑤  ∈  Fin ) | 
						
							| 41 |  | xpfi | ⊢ ( ( { 𝑤 }  ∈  Fin  ∧  𝒫  𝑤  ∈  Fin )  →  ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin ) | 
						
							| 42 | 29 40 41 | sylancr | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) )  →  ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin ) | 
						
							| 43 | 42 | ralrimiva | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ∀ 𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin ) | 
						
							| 44 |  | iunfi | ⊢ ( ( ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ∈  Fin  ∧  ∀ 𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin )  →  ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin ) | 
						
							| 45 | 28 43 44 | syl2anc | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin ) | 
						
							| 46 |  | ficardom | ⊢ ( ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin  →  ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) )  ∈  ω ) | 
						
							| 47 | 45 46 | syl | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) )  ∈  ω ) | 
						
							| 48 | 47 | fvresd | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( ( ♯  ↾  ω ) ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  =  ( ♯ ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) ) | 
						
							| 49 |  | hashcard | ⊢ ( ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin  →  ( ♯ ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  =  ( ♯ ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) | 
						
							| 50 | 45 49 | syl | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( ♯ ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  =  ( ♯ ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) | 
						
							| 51 |  | xp1st | ⊢ ( 𝑧  ∈  ( { 𝑤 }  ×  𝒫  𝑤 )  →  ( 1st  ‘ 𝑧 )  ∈  { 𝑤 } ) | 
						
							| 52 |  | elsni | ⊢ ( ( 1st  ‘ 𝑧 )  ∈  { 𝑤 }  →  ( 1st  ‘ 𝑧 )  =  𝑤 ) | 
						
							| 53 | 51 52 | syl | ⊢ ( 𝑧  ∈  ( { 𝑤 }  ×  𝒫  𝑤 )  →  ( 1st  ‘ 𝑧 )  =  𝑤 ) | 
						
							| 54 | 53 | rgen | ⊢ ∀ 𝑧  ∈  ( { 𝑤 }  ×  𝒫  𝑤 ) ( 1st  ‘ 𝑧 )  =  𝑤 | 
						
							| 55 | 54 | rgenw | ⊢ ∀ 𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ∀ 𝑧  ∈  ( { 𝑤 }  ×  𝒫  𝑤 ) ( 1st  ‘ 𝑧 )  =  𝑤 | 
						
							| 56 |  | invdisj | ⊢ ( ∀ 𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ∀ 𝑧  ∈  ( { 𝑤 }  ×  𝒫  𝑤 ) ( 1st  ‘ 𝑧 )  =  𝑤  →  Disj  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) | 
						
							| 57 | 55 56 | mp1i | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  Disj  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) | 
						
							| 58 | 28 42 57 | hashiun | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( ♯ ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) )  =  Σ 𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( ♯ ‘ ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) | 
						
							| 59 |  | sneq | ⊢ ( 𝑤  =  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  →  { 𝑤 }  =  { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) } ) | 
						
							| 60 |  | pweq | ⊢ ( 𝑤  =  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  →  𝒫  𝑤  =  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) | 
						
							| 61 | 59 60 | xpeq12d | ⊢ ( 𝑤  =  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  →  ( { 𝑤 }  ×  𝒫  𝑤 )  =  ( { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ×  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) | 
						
							| 62 | 61 | fveq2d | ⊢ ( 𝑤  =  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  →  ( ♯ ‘ ( { 𝑤 }  ×  𝒫  𝑤 ) )  =  ( ♯ ‘ ( { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ×  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) ) | 
						
							| 63 |  | elinel2 | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  𝑥  ∈  Fin ) | 
						
							| 64 |  | f1of1 | ⊢ ( ◡ ( ♯  ↾  ω ) : ℕ0 –1-1-onto→ ω  →  ◡ ( ♯  ↾  ω ) : ℕ0 –1-1→ ω ) | 
						
							| 65 | 14 64 | ax-mp | ⊢ ◡ ( ♯  ↾  ω ) : ℕ0 –1-1→ ω | 
						
							| 66 |  | elinel1 | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  𝑥  ∈  𝒫  ℕ0 ) | 
						
							| 67 | 66 | elpwid | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  𝑥  ⊆  ℕ0 ) | 
						
							| 68 |  | f1ores | ⊢ ( ( ◡ ( ♯  ↾  ω ) : ℕ0 –1-1→ ω  ∧  𝑥  ⊆  ℕ0 )  →  ( ◡ ( ♯  ↾  ω )  ↾  𝑥 ) : 𝑥 –1-1-onto→ ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) | 
						
							| 69 | 65 67 68 | sylancr | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( ◡ ( ♯  ↾  ω )  ↾  𝑥 ) : 𝑥 –1-1-onto→ ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) | 
						
							| 70 |  | fvres | ⊢ ( 𝑦  ∈  𝑥  →  ( ( ◡ ( ♯  ↾  ω )  ↾  𝑥 ) ‘ 𝑦 )  =  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) | 
						
							| 71 | 70 | adantl | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ( ◡ ( ♯  ↾  ω )  ↾  𝑥 ) ‘ 𝑦 )  =  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) | 
						
							| 72 |  | hashcl | ⊢ ( ( { 𝑤 }  ×  𝒫  𝑤 )  ∈  Fin  →  ( ♯ ‘ ( { 𝑤 }  ×  𝒫  𝑤 ) )  ∈  ℕ0 ) | 
						
							| 73 |  | nn0cn | ⊢ ( ( ♯ ‘ ( { 𝑤 }  ×  𝒫  𝑤 ) )  ∈  ℕ0  →  ( ♯ ‘ ( { 𝑤 }  ×  𝒫  𝑤 ) )  ∈  ℂ ) | 
						
							| 74 | 42 72 73 | 3syl | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) )  →  ( ♯ ‘ ( { 𝑤 }  ×  𝒫  𝑤 ) )  ∈  ℂ ) | 
						
							| 75 | 62 63 69 71 74 | fsumf1o | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  Σ 𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( ♯ ‘ ( { 𝑤 }  ×  𝒫  𝑤 ) )  =  Σ 𝑦  ∈  𝑥 ( ♯ ‘ ( { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ×  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) ) | 
						
							| 76 |  | snfi | ⊢ { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ∈  Fin | 
						
							| 77 | 67 | sselda | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  𝑦  ∈  ℕ0 ) | 
						
							| 78 |  | f1of | ⊢ ( ◡ ( ♯  ↾  ω ) : ℕ0 –1-1-onto→ ω  →  ◡ ( ♯  ↾  ω ) : ℕ0 ⟶ ω ) | 
						
							| 79 | 14 78 | ax-mp | ⊢ ◡ ( ♯  ↾  ω ) : ℕ0 ⟶ ω | 
						
							| 80 | 79 | ffvelcdmi | ⊢ ( 𝑦  ∈  ℕ0  →  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  ω ) | 
						
							| 81 | 77 80 | syl | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  ω ) | 
						
							| 82 | 35 81 | sselid | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  Fin ) | 
						
							| 83 |  | pwfi | ⊢ ( ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  Fin  ↔  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  Fin ) | 
						
							| 84 | 82 83 | sylib | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  Fin ) | 
						
							| 85 |  | hashxp | ⊢ ( ( { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ∈  Fin  ∧  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  Fin )  →  ( ♯ ‘ ( { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ×  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) )  =  ( ( ♯ ‘ { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) } )  ·  ( ♯ ‘ 𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) ) | 
						
							| 86 | 76 84 85 | sylancr | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ♯ ‘ ( { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ×  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) )  =  ( ( ♯ ‘ { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) } )  ·  ( ♯ ‘ 𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) ) | 
						
							| 87 |  | hashsng | ⊢ ( ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  ω  →  ( ♯ ‘ { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) } )  =  1 ) | 
						
							| 88 | 81 87 | syl | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ♯ ‘ { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) } )  =  1 ) | 
						
							| 89 |  | hashpw | ⊢ ( ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 )  ∈  Fin  →  ( ♯ ‘ 𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) )  =  ( 2 ↑ ( ♯ ‘ ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) ) | 
						
							| 90 | 82 89 | syl | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ♯ ‘ 𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) )  =  ( 2 ↑ ( ♯ ‘ ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) ) | 
						
							| 91 | 81 | fvresd | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ( ♯  ↾  ω ) ‘ ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) )  =  ( ♯ ‘ ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) | 
						
							| 92 |  | f1ocnvfv2 | ⊢ ( ( ( ♯  ↾  ω ) : ω –1-1-onto→ ℕ0  ∧  𝑦  ∈  ℕ0 )  →  ( ( ♯  ↾  ω ) ‘ ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) )  =  𝑦 ) | 
						
							| 93 | 3 77 92 | sylancr | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ( ♯  ↾  ω ) ‘ ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) )  =  𝑦 ) | 
						
							| 94 | 91 93 | eqtr3d | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ♯ ‘ ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) )  =  𝑦 ) | 
						
							| 95 | 94 | oveq2d | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( 2 ↑ ( ♯ ‘ ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) )  =  ( 2 ↑ 𝑦 ) ) | 
						
							| 96 | 90 95 | eqtrd | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ♯ ‘ 𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) )  =  ( 2 ↑ 𝑦 ) ) | 
						
							| 97 | 88 96 | oveq12d | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ( ♯ ‘ { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) } )  ·  ( ♯ ‘ 𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) )  =  ( 1  ·  ( 2 ↑ 𝑦 ) ) ) | 
						
							| 98 |  | 2cn | ⊢ 2  ∈  ℂ | 
						
							| 99 |  | expcl | ⊢ ( ( 2  ∈  ℂ  ∧  𝑦  ∈  ℕ0 )  →  ( 2 ↑ 𝑦 )  ∈  ℂ ) | 
						
							| 100 | 98 77 99 | sylancr | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( 2 ↑ 𝑦 )  ∈  ℂ ) | 
						
							| 101 | 100 | mullidd | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( 1  ·  ( 2 ↑ 𝑦 ) )  =  ( 2 ↑ 𝑦 ) ) | 
						
							| 102 | 86 97 101 | 3eqtrd | ⊢ ( ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ∧  𝑦  ∈  𝑥 )  →  ( ♯ ‘ ( { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ×  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) )  =  ( 2 ↑ 𝑦 ) ) | 
						
							| 103 | 102 | sumeq2dv | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  Σ 𝑦  ∈  𝑥 ( ♯ ‘ ( { ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) }  ×  𝒫  ( ◡ ( ♯  ↾  ω ) ‘ 𝑦 ) ) )  =  Σ 𝑦  ∈  𝑥 ( 2 ↑ 𝑦 ) ) | 
						
							| 104 | 58 75 103 | 3eqtrd | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( ♯ ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) )  =  Σ 𝑦  ∈  𝑥 ( 2 ↑ 𝑦 ) ) | 
						
							| 105 | 48 50 104 | 3eqtrd | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  →  ( ( ♯  ↾  ω ) ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  =  Σ 𝑦  ∈  𝑥 ( 2 ↑ 𝑦 ) ) | 
						
							| 106 | 105 | mpteq2ia | ⊢ ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ( ♯  ↾  ω ) ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) )  =  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  Σ 𝑦  ∈  𝑥 ( 2 ↑ 𝑦 ) ) | 
						
							| 107 | 47 | adantl | ⊢ ( ( ⊤  ∧  𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin ) )  →  ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) )  ∈  ω ) | 
						
							| 108 | 27 | adantl | ⊢ ( ( ⊤  ∧  𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin ) )  →  ( ◡ ( ♯  ↾  ω )  “  𝑥 )  ∈  ( 𝒫  ω  ∩  Fin ) ) | 
						
							| 109 |  | eqidd | ⊢ ( ⊤  →  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) )  =  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) | 
						
							| 110 |  | eqidd | ⊢ ( ⊤  →  ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  =  ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) ) | 
						
							| 111 |  | iuneq1 | ⊢ ( 𝑧  =  ( ◡ ( ♯  ↾  ω )  “  𝑥 )  →  ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 )  =  ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) | 
						
							| 112 | 111 | fveq2d | ⊢ ( 𝑧  =  ( ◡ ( ♯  ↾  ω )  “  𝑥 )  →  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) )  =  ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) | 
						
							| 113 | 108 109 110 112 | fmptco | ⊢ ( ⊤  →  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) )  =  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) ) | 
						
							| 114 |  | f1of | ⊢ ( ( ♯  ↾  ω ) : ω –1-1-onto→ ℕ0  →  ( ♯  ↾  ω ) : ω ⟶ ℕ0 ) | 
						
							| 115 | 3 114 | mp1i | ⊢ ( ⊤  →  ( ♯  ↾  ω ) : ω ⟶ ℕ0 ) | 
						
							| 116 | 115 | feqmptd | ⊢ ( ⊤  →  ( ♯  ↾  ω )  =  ( 𝑦  ∈  ω  ↦  ( ( ♯  ↾  ω ) ‘ 𝑦 ) ) ) | 
						
							| 117 |  | fveq2 | ⊢ ( 𝑦  =  ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) )  →  ( ( ♯  ↾  ω ) ‘ 𝑦 )  =  ( ( ♯  ↾  ω ) ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) ) | 
						
							| 118 | 107 113 116 117 | fmptco | ⊢ ( ⊤  →  ( ( ♯  ↾  ω )  ∘  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) )  =  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ( ♯  ↾  ω ) ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) ) ) | 
						
							| 119 | 118 | mptru | ⊢ ( ( ♯  ↾  ω )  ∘  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) )  =  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ( ♯  ↾  ω ) ‘ ( card ‘ ∪  𝑤  ∈  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ( { 𝑤 }  ×  𝒫  𝑤 ) ) ) ) | 
						
							| 120 | 106 119 1 | 3eqtr4i | ⊢ ( ( ♯  ↾  ω )  ∘  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) )  =  𝐹 | 
						
							| 121 |  | f1oeq1 | ⊢ ( ( ( ♯  ↾  ω )  ∘  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) )  =  𝐹  →  ( ( ( ♯  ↾  ω )  ∘  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ℕ0  ↔  𝐹 : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ℕ0 ) ) | 
						
							| 122 | 120 121 | ax-mp | ⊢ ( ( ( ♯  ↾  ω )  ∘  ( ( 𝑧  ∈  ( 𝒫  ω  ∩  Fin )  ↦  ( card ‘ ∪  𝑤  ∈  𝑧 ( { 𝑤 }  ×  𝒫  𝑤 ) ) )  ∘  ( 𝑥  ∈  ( 𝒫  ℕ0  ∩  Fin )  ↦  ( ◡ ( ♯  ↾  ω )  “  𝑥 ) ) ) ) : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ℕ0  ↔  𝐹 : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ℕ0 ) | 
						
							| 123 | 20 122 | mpbi | ⊢ 𝐹 : ( 𝒫  ℕ0  ∩  Fin ) –1-1-onto→ ℕ0 |