| Step | Hyp | Ref | Expression | 
						
							| 1 |  | unblem.2 | ⊢ 𝐹  =  ( rec ( ( 𝑥  ∈  V  ↦  ∩  ( 𝐴  ∖  suc  𝑥 ) ) ,  ∩  𝐴 )  ↾  ω ) | 
						
							| 2 |  | omsson | ⊢ ω  ⊆  On | 
						
							| 3 |  | sstr | ⊢ ( ( 𝐴  ⊆  ω  ∧  ω  ⊆  On )  →  𝐴  ⊆  On ) | 
						
							| 4 | 2 3 | mpan2 | ⊢ ( 𝐴  ⊆  ω  →  𝐴  ⊆  On ) | 
						
							| 5 | 4 | adantr | ⊢ ( ( 𝐴  ⊆  ω  ∧  ∀ 𝑤  ∈  ω ∃ 𝑣  ∈  𝐴 𝑤  ∈  𝑣 )  →  𝐴  ⊆  On ) | 
						
							| 6 |  | frfnom | ⊢ ( rec ( ( 𝑥  ∈  V  ↦  ∩  ( 𝐴  ∖  suc  𝑥 ) ) ,  ∩  𝐴 )  ↾  ω )  Fn  ω | 
						
							| 7 | 1 | fneq1i | ⊢ ( 𝐹  Fn  ω  ↔  ( rec ( ( 𝑥  ∈  V  ↦  ∩  ( 𝐴  ∖  suc  𝑥 ) ) ,  ∩  𝐴 )  ↾  ω )  Fn  ω ) | 
						
							| 8 | 6 7 | mpbir | ⊢ 𝐹  Fn  ω | 
						
							| 9 | 1 | unblem2 | ⊢ ( ( 𝐴  ⊆  ω  ∧  ∀ 𝑤  ∈  ω ∃ 𝑣  ∈  𝐴 𝑤  ∈  𝑣 )  →  ( 𝑧  ∈  ω  →  ( 𝐹 ‘ 𝑧 )  ∈  𝐴 ) ) | 
						
							| 10 | 9 | ralrimiv | ⊢ ( ( 𝐴  ⊆  ω  ∧  ∀ 𝑤  ∈  ω ∃ 𝑣  ∈  𝐴 𝑤  ∈  𝑣 )  →  ∀ 𝑧  ∈  ω ( 𝐹 ‘ 𝑧 )  ∈  𝐴 ) | 
						
							| 11 |  | ffnfv | ⊢ ( 𝐹 : ω ⟶ 𝐴  ↔  ( 𝐹  Fn  ω  ∧  ∀ 𝑧  ∈  ω ( 𝐹 ‘ 𝑧 )  ∈  𝐴 ) ) | 
						
							| 12 | 11 | biimpri | ⊢ ( ( 𝐹  Fn  ω  ∧  ∀ 𝑧  ∈  ω ( 𝐹 ‘ 𝑧 )  ∈  𝐴 )  →  𝐹 : ω ⟶ 𝐴 ) | 
						
							| 13 | 8 10 12 | sylancr | ⊢ ( ( 𝐴  ⊆  ω  ∧  ∀ 𝑤  ∈  ω ∃ 𝑣  ∈  𝐴 𝑤  ∈  𝑣 )  →  𝐹 : ω ⟶ 𝐴 ) | 
						
							| 14 | 1 | unblem3 | ⊢ ( ( 𝐴  ⊆  ω  ∧  ∀ 𝑤  ∈  ω ∃ 𝑣  ∈  𝐴 𝑤  ∈  𝑣 )  →  ( 𝑧  ∈  ω  →  ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐹 ‘ suc  𝑧 ) ) ) | 
						
							| 15 | 14 | ralrimiv | ⊢ ( ( 𝐴  ⊆  ω  ∧  ∀ 𝑤  ∈  ω ∃ 𝑣  ∈  𝐴 𝑤  ∈  𝑣 )  →  ∀ 𝑧  ∈  ω ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐹 ‘ suc  𝑧 ) ) | 
						
							| 16 |  | omsmo | ⊢ ( ( ( 𝐴  ⊆  On  ∧  𝐹 : ω ⟶ 𝐴 )  ∧  ∀ 𝑧  ∈  ω ( 𝐹 ‘ 𝑧 )  ∈  ( 𝐹 ‘ suc  𝑧 ) )  →  𝐹 : ω –1-1→ 𝐴 ) | 
						
							| 17 | 5 13 15 16 | syl21anc | ⊢ ( ( 𝐴  ⊆  ω  ∧  ∀ 𝑤  ∈  ω ∃ 𝑣  ∈  𝐴 𝑤  ∈  𝑣 )  →  𝐹 : ω –1-1→ 𝐴 ) |