Rascal Language ReferenceExpressionsValuesBooleanBoolean NegationOn this pageBoolean Negationrascal-0.28.2SynopsisThe not operator on Boolean values.Syntax! ExpTypes//Exp! ExpboolboolDescriptionThe not operator on Boolean values defined as follows:Exp! ExptruefalsefalsetrueExamplesrascal>!true;bool: false