Exponential Integral(redirected from Expint)
exponential integral[‚ek·spə′nen·chəl ′int·ə·grəl]
The function defined to be the integral from x to ∞ of (e -t / t) dt for x positive.
a special function defined by the integral
This integral cannot be expressed in closed form through elementary functions. If x > 0, then the integral is understood in the sense of its principal value: