>I get .F., .T., for the first two comparisons.
Yeah I had them backwards.

The string comparison rules are;

SET EXACT OFF
1. The strings are considered equal
2. The strings are compared one character at a time
3. If a mismatched character is hit they are considered unequal
4. The comparison stops when the string on the right side of the = is exhausted

SET EXACT ON
1.  The shorter of the two strings is padded on the right with spaces to be
    equal in length to the longer

the rest of the comparison is the same as SET EXACT OFF

==
The string are compared the same as as set exact off, plus
5. If the strings are still equal their lengths are compared and the result is 
   returned