wikipedia(url, title)
wikipedia title
i1 : wikipedia "Bessel function" o1 = Bessel function (see https://en.wikipedia.org/wiki/Bessel_function ) o1 : HREF
i2 : html oo o2 = <a href="https://en.wikipedia.org/wiki/Bessel_function">Bessel function</a>
i3 : wikipedia("Bessel_function#Definitions", "Bessel function") o3 = Bessel function (see https://en.wikipedia.org/wiki/Bessel_function#Definitions ) o3 : HREF
i4 : html oo o4 = <a href="https://en.wikipedia.org/wiki/Bessel_function#Definitions"> Bessel function</a>
The object wikipedia is a method function.