By the Curry-Howard correspondence no code should be able to be copyrighted since every program is a formal mathematical proof. However judges aren't usually mathematicians with a background in Computing Science so it's of little consequence.
No algorithm should be copyright-able but your expression of that algorithm should. Programming language choice, variable names, comments, code-style, etc are all creative expressions which are relatively independent of the underlying math.
Are they though? They are minor variations in technical language to describe the same mathematical reality.