Exponential​(PeterO.​Numbers.​EDecimal,​PeterO.​Numbers.​EContext)

e to the x to the precision of context:
x = k ln 2 + r with |r| at most half of ln 2, r halved
ten times, the Taylor series there -- twenty-five terms at a hundred digits -- and
ten squarings and the power of two back, in fixed point. PeterO's
Exp(PeterO.Numbers.EContext) is three hundred microseconds at a hundred
digits; this is about ten. An argument beyond a thousand in magnitude, and an
infinity or NaN, are PeterO's answers.
https://github.com/asc-community/AngouriMath/issues/1338