“…Thus, even when .~and C are far apart, (A~C~, x0 C)) is not a purely topological quantity that depends only on the linking number of~and C. Of course, in higher orders in the strong coupling expansion, the behavior of~becomes still more complicated. Similarly, if a loop C links with two different surfaces .~,and~2' the operator A~'~,,2(.Z1, .12, x0 C) acquires a factor (1/n)~~(a,) each time the electric flux tube crosses .1~and a factor (1/n~)~°~(a2) each time it crosses 12 (in the leading order of the strong-coupling expansion). Because of confinement, the string world-sheets combine as trivial charge eigenstates rather than group eigenstates, even though both are defined with respect to a common basepoint.…”