protected static Ptg calcIsNumber( Ptg[] operands )
	{
		Ptg[] allops = PtgCalculator.getAllComponents( operands );
		if( allops.length > 1 )
		{
			return new PtgBool( false );
		}
		Object o = operands[0].getValue();
		try
		{
			Float f = (Float) o;
			return new PtgBool( true );
		}
		catch( ClassCastException e )
		{
			try
			{
				Double d = (Double) o;
				return new PtgBool( true );
			}
			catch( ClassCastException ee )
			{
				try
				{
					Integer ii = (Integer) o;
					return new PtgBool( true );
				}
				catch( ClassCastException eee )
				{
				}
				;
			}
			;
		}
		return new PtgBool( false );
	}