The keywords of cool are: \(\bf class\), \(\bf else\), \(\bf false\), \(\bf fi\), \(\bf if\), \(\bf in\), \(\bf inherits\), \(\bf isvoid\), \(\bf let\), \(\bf loop\), \(\bf pool\), \(\bf then\), \(\bf while\), \(\bf case\), \(\bf esac\), \(\bf new\), \(\bf of\), \(\bf not\), \(\bf true\). Except for the constants \(\bf true\) and \(\bf false\), keywords are case insensitive.
To conform to the rules for other objects, the first letter of \(\bf true\) and \(\bf false\) must be lowercase; the trailing letters may be upper or lower case. Thus \(\bf FALse\) is not a keyword but a type identifier.