| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ovex | ⊢ ( ℂ  ↑pm  𝑆 )  ∈  V | 
						
							| 2 | 1 | rabex | ⊢ { 𝑓  ∈  ( ℂ  ↑pm  𝑆 )  ∣  ( ( 𝑆  D𝑛  𝑓 ) ‘ 𝑛 )  ∈  ( dom  𝑓 –cn→ ℂ ) }  ∈  V | 
						
							| 3 |  | eqid | ⊢ ( 𝑛  ∈  ℕ0  ↦  { 𝑓  ∈  ( ℂ  ↑pm  𝑆 )  ∣  ( ( 𝑆  D𝑛  𝑓 ) ‘ 𝑛 )  ∈  ( dom  𝑓 –cn→ ℂ ) } )  =  ( 𝑛  ∈  ℕ0  ↦  { 𝑓  ∈  ( ℂ  ↑pm  𝑆 )  ∣  ( ( 𝑆  D𝑛  𝑓 ) ‘ 𝑛 )  ∈  ( dom  𝑓 –cn→ ℂ ) } ) | 
						
							| 4 | 2 3 | fnmpti | ⊢ ( 𝑛  ∈  ℕ0  ↦  { 𝑓  ∈  ( ℂ  ↑pm  𝑆 )  ∣  ( ( 𝑆  D𝑛  𝑓 ) ‘ 𝑛 )  ∈  ( dom  𝑓 –cn→ ℂ ) } )  Fn  ℕ0 | 
						
							| 5 |  | cpnfval | ⊢ ( 𝑆  ⊆  ℂ  →  ( 𝓑C𝑛 ‘ 𝑆 )  =  ( 𝑛  ∈  ℕ0  ↦  { 𝑓  ∈  ( ℂ  ↑pm  𝑆 )  ∣  ( ( 𝑆  D𝑛  𝑓 ) ‘ 𝑛 )  ∈  ( dom  𝑓 –cn→ ℂ ) } ) ) | 
						
							| 6 | 5 | fneq1d | ⊢ ( 𝑆  ⊆  ℂ  →  ( ( 𝓑C𝑛 ‘ 𝑆 )  Fn  ℕ0  ↔  ( 𝑛  ∈  ℕ0  ↦  { 𝑓  ∈  ( ℂ  ↑pm  𝑆 )  ∣  ( ( 𝑆  D𝑛  𝑓 ) ‘ 𝑛 )  ∈  ( dom  𝑓 –cn→ ℂ ) } )  Fn  ℕ0 ) ) | 
						
							| 7 | 4 6 | mpbiri | ⊢ ( 𝑆  ⊆  ℂ  →  ( 𝓑C𝑛 ‘ 𝑆 )  Fn  ℕ0 ) |