| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eqid | ⊢ ( 𝑗  ∈  ℕ  ↦  ( 2 ↑ - ( ! ‘ 𝑗 ) ) )  =  ( 𝑗  ∈  ℕ  ↦  ( 2 ↑ - ( ! ‘ 𝑗 ) ) ) | 
						
							| 2 |  | fveq2 | ⊢ ( 𝑘  =  𝑖  →  ( ! ‘ 𝑘 )  =  ( ! ‘ 𝑖 ) ) | 
						
							| 3 | 2 | negeqd | ⊢ ( 𝑘  =  𝑖  →  - ( ! ‘ 𝑘 )  =  - ( ! ‘ 𝑖 ) ) | 
						
							| 4 | 3 | oveq2d | ⊢ ( 𝑘  =  𝑖  →  ( 2 ↑ - ( ! ‘ 𝑘 ) )  =  ( 2 ↑ - ( ! ‘ 𝑖 ) ) ) | 
						
							| 5 | 4 | cbvsumv | ⊢ Σ 𝑘  ∈  ℕ ( 2 ↑ - ( ! ‘ 𝑘 ) )  =  Σ 𝑖  ∈  ℕ ( 2 ↑ - ( ! ‘ 𝑖 ) ) | 
						
							| 6 |  | fveq2 | ⊢ ( 𝑗  =  𝑖  →  ( ! ‘ 𝑗 )  =  ( ! ‘ 𝑖 ) ) | 
						
							| 7 | 6 | negeqd | ⊢ ( 𝑗  =  𝑖  →  - ( ! ‘ 𝑗 )  =  - ( ! ‘ 𝑖 ) ) | 
						
							| 8 | 7 | oveq2d | ⊢ ( 𝑗  =  𝑖  →  ( 2 ↑ - ( ! ‘ 𝑗 ) )  =  ( 2 ↑ - ( ! ‘ 𝑖 ) ) ) | 
						
							| 9 |  | ovex | ⊢ ( 2 ↑ - ( ! ‘ 𝑖 ) )  ∈  V | 
						
							| 10 | 8 1 9 | fvmpt | ⊢ ( 𝑖  ∈  ℕ  →  ( ( 𝑗  ∈  ℕ  ↦  ( 2 ↑ - ( ! ‘ 𝑗 ) ) ) ‘ 𝑖 )  =  ( 2 ↑ - ( ! ‘ 𝑖 ) ) ) | 
						
							| 11 | 10 | eqcomd | ⊢ ( 𝑖  ∈  ℕ  →  ( 2 ↑ - ( ! ‘ 𝑖 ) )  =  ( ( 𝑗  ∈  ℕ  ↦  ( 2 ↑ - ( ! ‘ 𝑗 ) ) ) ‘ 𝑖 ) ) | 
						
							| 12 | 11 | sumeq2i | ⊢ Σ 𝑖  ∈  ℕ ( 2 ↑ - ( ! ‘ 𝑖 ) )  =  Σ 𝑖  ∈  ℕ ( ( 𝑗  ∈  ℕ  ↦  ( 2 ↑ - ( ! ‘ 𝑗 ) ) ) ‘ 𝑖 ) | 
						
							| 13 | 5 12 | eqtri | ⊢ Σ 𝑘  ∈  ℕ ( 2 ↑ - ( ! ‘ 𝑘 ) )  =  Σ 𝑖  ∈  ℕ ( ( 𝑗  ∈  ℕ  ↦  ( 2 ↑ - ( ! ‘ 𝑗 ) ) ) ‘ 𝑖 ) | 
						
							| 14 |  | eqid | ⊢ ( 𝑙  ∈  ℕ  ↦  Σ 𝑖  ∈  ( 1 ... 𝑙 ) ( ( 𝑗  ∈  ℕ  ↦  ( 2 ↑ - ( ! ‘ 𝑗 ) ) ) ‘ 𝑖 ) )  =  ( 𝑙  ∈  ℕ  ↦  Σ 𝑖  ∈  ( 1 ... 𝑙 ) ( ( 𝑗  ∈  ℕ  ↦  ( 2 ↑ - ( ! ‘ 𝑗 ) ) ) ‘ 𝑖 ) ) | 
						
							| 15 | 1 13 14 | aaliou3lem9 | ⊢ ¬  Σ 𝑘  ∈  ℕ ( 2 ↑ - ( ! ‘ 𝑘 ) )  ∈  𝔸 | 
						
							| 16 | 15 | nelir | ⊢ Σ 𝑘  ∈  ℕ ( 2 ↑ - ( ! ‘ 𝑘 ) )  ∉  𝔸 |