Bug #783: mathn e$B$7$?>l9g$Ne(B ** e$B$N?6Iq$$$K0l4S@-$,$J$$e(B
http://redmine.ruby-lang.org/issues/show/783
e$B5/I<<Te(B: tadayoshi funaba
e$B%9%F!<%?%9e(B: Open, e$BM%@hEYe(B: Normal
$ ./ruby -r mathn -e ‘p (-8)**(1/3)’
Complex(1.0, 1.73205080756888)
e$B0J2<$b>e$HF1$8$h$&$J7k2L$K$J$k$Y$-$@$H;W$$$^$9!#e(B
$ ./ruby -r mathn -e ‘p (-8.0)**(1/3)’
NaN
$ ./ruby -r mathn -e ‘p (-8)**(1.0/3)’
NaN