Orientation system

[Raymond Rivest]

I have a nice question for every one.....

It's a question of user interface and how you would expect
a software to behave.....

You have a line along of which you want certain symbols to 
be drawn using a specific orentation....  If you'd say
"I want that symbol to be drawn +30 degrees added to the
vector direction", where would you expect the + to go ?

Left of Right ?

Meaning...  When adding angles, where do you add, where do you
substract....?