def gst_value_from_inclusive(amount, gst_rate):
    """Calculate GST component from a GST inclusive total.
    
    GST amount calculated as amount - (1 + gst_rate)).
    
    Args:
        amount (float): GST inclusive amount
        gst_rate (float): GST rate to apply.
        
    Returns:
        gst_component (float): Calculated GST component.
    """          
    return amount - (amount / (1 + gst_rate))