Metamath Proof Explorer
		
		
		
		Description:  The zeroth bit of an odd number is zero.  (Contributed by Mario Carneiro, 5-Sep-2016)  (Revised by AV, 19-Jun-2020)
		
			
				
					|  |  | Ref | Expression | 
				
					|  | Assertion | bits0oALTV | ⊢  ( 𝑁  ∈   Odd   →  0  ∈  ( bits ‘ 𝑁 ) ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oddz | ⊢ ( 𝑁  ∈   Odd   →  𝑁  ∈  ℤ ) | 
						
							| 2 |  | bits0ALTV | ⊢ ( 𝑁  ∈  ℤ  →  ( 0  ∈  ( bits ‘ 𝑁 )  ↔  𝑁  ∈   Odd  ) ) | 
						
							| 3 | 1 2 | syl | ⊢ ( 𝑁  ∈   Odd   →  ( 0  ∈  ( bits ‘ 𝑁 )  ↔  𝑁  ∈   Odd  ) ) | 
						
							| 4 | 3 | ibir | ⊢ ( 𝑁  ∈   Odd   →  0  ∈  ( bits ‘ 𝑁 ) ) |