The **Harkonen subflux algorithm** is used to approximate the time it takes for an isochloric wave function to collapse in a closed VX system. It was discovered by Erwin Harkonen in 1974 during his most active years. The function is given as follows:

In the formula, *δ* is delta, *g* is the fixed-volume gamma function, *i* is interphase potential, and *x* is flux capacity. Although the accuracy of the approximation has been widely debated, most agree that error should be at most a few nanoseconds. VX pioneer Katherine Yalgeth estimated it to 3 nanoseconds.