//this.intStack have the position of the operator
Expression r, exp = this.expressionStack[this.expressionPtr];
if (op == MINUS) {
if (exp instanceof IntLiteral) {
IntLiteral intLiteral = (IntLiteral) exp;
IntLiteral convertToMinValue = intLiteral.convertToMinValue();
if (convertToMinValue == intLiteral) {
// not a min value literal so we convert it to an unary expression
r = new UnaryExpression(exp, op);
} else {
r = convertToMinValue;