| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oveq2 | ⊢ ( 𝑁  =  0  →  ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 𝑁 )  =  ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 0 ) ) | 
						
							| 2 |  | clwwlk0on0 | ⊢ ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 0 )  =  ∅ | 
						
							| 3 | 1 2 | eqtrdi | ⊢ ( 𝑁  =  0  →  ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 𝑁 )  =  ∅ ) | 
						
							| 4 | 3 | a1d | ⊢ ( 𝑁  =  0  →  ( ¬  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ )  →  ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 𝑁 )  =  ∅ ) ) | 
						
							| 5 |  | simprl | ⊢ ( ( 𝑁  ≠  0  ∧  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ0 ) )  →  𝑋  ∈  ( Vtx ‘ 𝐺 ) ) | 
						
							| 6 |  | elnnne0 | ⊢ ( 𝑁  ∈  ℕ  ↔  ( 𝑁  ∈  ℕ0  ∧  𝑁  ≠  0 ) ) | 
						
							| 7 | 6 | simplbi2 | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝑁  ≠  0  →  𝑁  ∈  ℕ ) ) | 
						
							| 8 | 7 | adantl | ⊢ ( ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ0 )  →  ( 𝑁  ≠  0  →  𝑁  ∈  ℕ ) ) | 
						
							| 9 | 8 | impcom | ⊢ ( ( 𝑁  ≠  0  ∧  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ0 ) )  →  𝑁  ∈  ℕ ) | 
						
							| 10 | 5 9 | jca | ⊢ ( ( 𝑁  ≠  0  ∧  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ0 ) )  →  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ ) ) | 
						
							| 11 | 10 | stoic1a | ⊢ ( ( 𝑁  ≠  0  ∧  ¬  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ ) )  →  ¬  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ0 ) ) | 
						
							| 12 |  | clwwlknonmpo | ⊢ ( ClWWalksNOn ‘ 𝐺 )  =  ( 𝑣  ∈  ( Vtx ‘ 𝐺 ) ,  𝑛  ∈  ℕ0  ↦  { 𝑤  ∈  ( 𝑛  ClWWalksN  𝐺 )  ∣  ( 𝑤 ‘ 0 )  =  𝑣 } ) | 
						
							| 13 | 12 | mpondm0 | ⊢ ( ¬  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ0 )  →  ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 𝑁 )  =  ∅ ) | 
						
							| 14 | 11 13 | syl | ⊢ ( ( 𝑁  ≠  0  ∧  ¬  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ ) )  →  ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 𝑁 )  =  ∅ ) | 
						
							| 15 | 14 | ex | ⊢ ( 𝑁  ≠  0  →  ( ¬  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ )  →  ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 𝑁 )  =  ∅ ) ) | 
						
							| 16 | 4 15 | pm2.61ine | ⊢ ( ¬  ( 𝑋  ∈  ( Vtx ‘ 𝐺 )  ∧  𝑁  ∈  ℕ )  →  ( 𝑋 ( ClWWalksNOn ‘ 𝐺 ) 𝑁 )  =  ∅ ) |