nl_tokens: the spherical arclength of the icosahedron s edges . Returns the arc length between two positions .
pl_tokens: function <mask> ( f1_φ, 1_λ,  f _φ, f 2 λ) { return 2 * asin ( sqrt ( pow ( sin ( ( f1_φ  2_φ)  / 2 , 2 + cos ( f1_φ) os( f 2_φ)  * p w(s i n(( f 1 _λ -  2 λ) /  2 , 2 ) ) ) ; }