pub fn range_check_v(&mut self, num: Var<C::N>, num_bits: usize) {
        let bits = self.num2bits_v(num);
        self.range(num_bits, bits.len()).for_each(|i, builder| {
            let bit = builder.get(&bits, i);
            builder.assert_var_eq(bit, C::N::zero());
        });
    }
Range checks a variable to a certain number of bits.
crates/recursion/compiler/src/ir/bits.rs