Just to clarify (or confuse):

¬ is the symbol for "not" in Boolean algebra. ^ is called "caret". It's used in computer languages to mean "raised to the power of". So 4^2 =16. ~ is "tilde" and is used by mathematicians to mean "approximately".

In the ASCII code (which defines the way characters are stored in computers) the original "apostrophe" character slanted forwards and was an opening single quote. The backward one was a single closing quote. However, those usages seem to have been subverted and the apostrophe is now usual vertical, though the closing one remains slanted.