## What *is* uninitialized memory?
How is this possible?
-The answer is that, in the "abstract machine" that is used to specify the behavior of our program, every byte in memory cannot just have a value in `0..256` (this is Rust/Ruby syntax for a left-inclusive right-exclusive range), it can also be "uninitialized".
+The answer is that, in the "abstract machine" that is used to specify the behavior of our program, every byte in memory cannot just have a value in `0..256` (this is Rust syntax for a left-inclusive right-exclusive range), it can also be "uninitialized".
Memory *remembers* if you initialized it.
The `x` that is passed to `always_return_true` is *not* the 8-bit representation of some number, it is an uninitialized byte.
Performing operations such as comparison on uninitialized bytes is [undefined behavior]({% post_url 2017-07-14-undefined-behavior %}).