Value1 <= Value2 ; "<";
Value2 > Value2; ">"
Building on Johan's answer, the result will need to be text instead of number for this to work properly.
If you need it to be a number for calculation purposes, you can have a second field that calculates out as text and displays the >/< signs.
Edit: Alternatively, you can just put < or > text objects on the layout and use Hide Object to display them as appropriate. Depends on your need.