use ArbitraryPrecision.frink

/** This tests your processor's built-in IEEE-754 floating-point math
    to see how bad it is for certain values of ln[x] around 1.
*/
setPrecision[100]
for i=1 to 17
{
   n = 1. + 10^-i
   a = ln[n]
   b = arbitraryLn[n]
   err = abs[a-b]/b
   println["$n\t$a\t" + formatSig[err,1,4]]
}