Function vstd::bits::lemma_u64_shl_is_mul

source · 
pub broadcast proof fn lemma_u64_shl_is_mul(x: u64, shift: u64)
Expand description
requires
0 <= shift < <u64>::BITS,
x * pow2(shift as nat) <= <u64>::MAX,
ensures
#[trigger] (x << shift) == x * pow2(shift as nat),

Proof that for x and n of type u64 , shifting x left by n is equivalent to multiplication of x by 2^n (provided no overflow).