nl_tokens: general nth root - ing
pl_tokens: function nthRoot ( num , nArg , precArg ) { // : Int -> Int -> Int -> Int var n = nArg || 2 ; var prec = precArg || 12 ; <mask> x = 1 ; // Initial guess. for ( var i = 0 ; i < prec ; i ++ ) { x = 1 / n * ( ( n - 1 ) * x + ( num / Math . pow ( x , n - 1 ) ) ) ; } return x ; }