Fixed expressions to be able to do math with nested expressions.

Operand.h

@@ -10,8 +10,7 @@ namespace jet {
     public:
       Operand(coreutils::ZString &in);
 
-      bool isNumber();
-      bool isString();
+      bool isNumber;
 
       ///
       /// boolean is set by internal processes to return the boolean
@@ -21,8 +20,6 @@ namespace jet {
       bool boolean;
       coreutils::MString string;
       
-    private:
-//      dataType enum ={};
       double doubleValue;