public override bool equals(Object obj)
{
if (this == obj)
{
return(true);
}
else if (!(obj instanceof Expr))
{
return(false);
}
Expr expr = (Expr)obj;
if (!isLiteral() || !expr.isLiteral())
{
return(false);
}
return(evalConstant().equals(expr.evalConstant()));
}