Expert System - Australian Flags by McGoo Software

Based on the responses you have made:

The flag is probably the Australian National Flag

Conclusion Notes:

in vexillological terms, the Australian flag is a defaced British blue ensign (the State Ensign of the United Kingdom). In the upper hoist (canton) of the flag is the Union Flag (i.e. the State and Civil Flag of the United Kingdom, popularly called the Union Jack). On the fly are 5 white stars, representing the Southern Cross, a constellation of stars generally only visible in the southern hemisphere. Each of these stars has 7 points except for the smallest star which has only five. Directly below the Union Flag is a large 7 pointed white star called the Federation Star, representing the federation of the colonies of Australia on 1 January 1901. There is one point for each of the six original states, and one to represent all of Australia's internal and external territories.

Expert System Rule:

IF on the flag the Southern Cross is visible
AND on the flag there is a Union Jack present
AND the field of the flag is navy blue
AND above the Southern Cross there is no crown
THEN the flag is probably the Australian National Flag.

Calculated Certainty Factor: 0.48 = probably