Imagine having a TheSaurus for programming language Keywords and Concepts that responds to queryes with synonyms and antonyms that are strictly other language keywords or operands. Asking for ">=" the user will be presented with "<=" as antonym and ">" as a synonym (it's an example). Which Antonym will you expect to find searching for the term "for each"?
If this is OT let me know. I'm not so at pace with the community since years.
"For each" wouldn't have an antonym. Your question reminds me of this other riddle: "What is the opposite of a circle?"