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diff --git a/src/pkg/math/jn.go b/src/pkg/math/jn.go
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--- a/src/pkg/math/jn.go
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@@ -1,306 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package math
-
-/*
-	Bessel function of the first and second kinds of order n.
-*/
-
-// The original C code and the long comment below are
-// from FreeBSD's /usr/src/lib/msun/src/e_jn.c and
-// came with this notice.  The go code is a simplified
-// version of the original C.
-//
-// ====================================================
-// Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
-//
-// Developed at SunPro, a Sun Microsystems, Inc. business.
-// Permission to use, copy, modify, and distribute this
-// software is freely granted, provided that this notice
-// is preserved.
-// ====================================================
-//
-// __ieee754_jn(n, x), __ieee754_yn(n, x)
-// floating point Bessel's function of the 1st and 2nd kind
-// of order n
-//
-// Special cases:
-//      y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal;
-//      y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal.
-// Note 2. About jn(n,x), yn(n,x)
-//      For n=0, j0(x) is called,
-//      for n=1, j1(x) is called,
-//      for n<x, forward recursion is used starting
-//      from values of j0(x) and j1(x).
-//      for n>x, a continued fraction approximation to
-//      j(n,x)/j(n-1,x) is evaluated and then backward
-//      recursion is used starting from a supposed value
-//      for j(n,x). The resulting value of j(0,x) is
-//      compared with the actual value to correct the
-//      supposed value of j(n,x).
-//
-//      yn(n,x) is similar in all respects, except
-//      that forward recursion is used for all
-//      values of n>1.
-
-// Jn returns the order-n Bessel function of the first kind.
-//
-// Special cases are:
-//	Jn(n, ±Inf) = 0
-//	Jn(n, NaN) = NaN
-func Jn(n int, x float64) float64 {
-	const (
-		TwoM29 = 1.0 / (1 << 29) // 2**-29 0x3e10000000000000
-		Two302 = 1 << 302        // 2**302 0x52D0000000000000
-	)
-	// special cases
-	switch {
-	case IsNaN(x):
-		return x
-	case IsInf(x, 0):
-		return 0
-	}
-	// J(-n, x) = (-1)**n * J(n, x), J(n, -x) = (-1)**n * J(n, x)
-	// Thus, J(-n, x) = J(n, -x)
-
-	if n == 0 {
-		return J0(x)
-	}
-	if x == 0 {
-		return 0
-	}
-	if n < 0 {
-		n, x = -n, -x
-	}
-	if n == 1 {
-		return J1(x)
-	}
-	sign := false
-	if x < 0 {
-		x = -x
-		if n&1 == 1 {
-			sign = true // odd n and negative x
-		}
-	}
-	var b float64
-	if float64(n) <= x {
-		// Safe to use J(n+1,x)=2n/x *J(n,x)-J(n-1,x)
-		if x >= Two302 { // x > 2**302
-
-			// (x >> n**2)
-			//          Jn(x) = cos(x-(2n+1)*pi/4)*sqrt(2/x*pi)
-			//          Yn(x) = sin(x-(2n+1)*pi/4)*sqrt(2/x*pi)
-			//          Let s=sin(x), c=cos(x),
-			//              xn=x-(2n+1)*pi/4, sqt2 = sqrt(2),then
-			//
-			//                 n    sin(xn)*sqt2    cos(xn)*sqt2
-			//              ----------------------------------
-			//                 0     s-c             c+s
-			//                 1    -s-c            -c+s
-			//                 2    -s+c            -c-s
-			//                 3     s+c             c-s
-
-			var temp float64
-			switch n & 3 {
-			case 0:
-				temp = Cos(x) + Sin(x)
-			case 1:
-				temp = -Cos(x) + Sin(x)
-			case 2:
-				temp = -Cos(x) - Sin(x)
-			case 3:
-				temp = Cos(x) - Sin(x)
-			}
-			b = (1 / SqrtPi) * temp / Sqrt(x)
-		} else {
-			b = J1(x)
-			for i, a := 1, J0(x); i < n; i++ {
-				a, b = b, b*(float64(i+i)/x)-a // avoid underflow
-			}
-		}
-	} else {
-		if x < TwoM29 { // x < 2**-29
-			// x is tiny, return the first Taylor expansion of J(n,x)
-			// J(n,x) = 1/n!*(x/2)**n  - ...
-
-			if n > 33 { // underflow
-				b = 0
-			} else {
-				temp := x * 0.5
-				b = temp
-				a := 1.0
-				for i := 2; i <= n; i++ {
-					a *= float64(i) // a = n!
-					b *= temp       // b = (x/2)**n
-				}
-				b /= a
-			}
-		} else {
-			// use backward recurrence
-			//                      x      x**2      x**2
-			//  J(n,x)/J(n-1,x) =  ----   ------   ------   .....
-			//                      2n  - 2(n+1) - 2(n+2)
-			//
-			//                      1      1        1
-			//  (for large x)   =  ----  ------   ------   .....
-			//                      2n   2(n+1)   2(n+2)
-			//                      -- - ------ - ------ -
-			//                       x     x         x
-			//
-			// Let w = 2n/x and h=2/x, then the above quotient
-			// is equal to the continued fraction:
-			//                  1
-			//      = -----------------------
-			//                     1
-			//         w - -----------------
-			//                        1
-			//              w+h - ---------
-			//                     w+2h - ...
-			//
-			// To determine how many terms needed, let
-			// Q(0) = w, Q(1) = w(w+h) - 1,
-			// Q(k) = (w+k*h)*Q(k-1) - Q(k-2),
-			// When Q(k) > 1e4	good for single
-			// When Q(k) > 1e9	good for double
-			// When Q(k) > 1e17	good for quadruple
-
-			// determine k
-			w := float64(n+n) / x
-			h := 2 / x
-			q0 := w
-			z := w + h
-			q1 := w*z - 1
-			k := 1
-			for q1 < 1e9 {
-				k += 1
-				z += h
-				q0, q1 = q1, z*q1-q0
-			}
-			m := n + n
-			t := 0.0
-			for i := 2 * (n + k); i >= m; i -= 2 {
-				t = 1 / (float64(i)/x - t)
-			}
-			a := t
-			b = 1
-			//  estimate log((2/x)**n*n!) = n*log(2/x)+n*ln(n)
-			//  Hence, if n*(log(2n/x)) > ...
-			//  single 8.8722839355e+01
-			//  double 7.09782712893383973096e+02
-			//  long double 1.1356523406294143949491931077970765006170e+04
-			//  then recurrent value may overflow and the result is
-			//  likely underflow to zero
-
-			tmp := float64(n)
-			v := 2 / x
-			tmp = tmp * Log(Abs(v*tmp))
-			if tmp < 7.09782712893383973096e+02 {
-				for i := n - 1; i > 0; i-- {
-					di := float64(i + i)
-					a, b = b, b*di/x-a
-					di -= 2
-				}
-			} else {
-				for i := n - 1; i > 0; i-- {
-					di := float64(i + i)
-					a, b = b, b*di/x-a
-					di -= 2
-					// scale b to avoid spurious overflow
-					if b > 1e100 {
-						a /= b
-						t /= b
-						b = 1
-					}
-				}
-			}
-			b = t * J0(x) / b
-		}
-	}
-	if sign {
-		return -b
-	}
-	return b
-}
-
-// Yn returns the order-n Bessel function of the second kind.
-//
-// Special cases are:
-//	Yn(n, +Inf) = 0
-//	Yn(n > 0, 0) = -Inf
-//	Yn(n < 0, 0) = +Inf if n is odd, -Inf if n is even
-//	Y1(n, x < 0) = NaN
-//	Y1(n, NaN) = NaN
-func Yn(n int, x float64) float64 {
-	const Two302 = 1 << 302 // 2**302 0x52D0000000000000
-	// special cases
-	switch {
-	case x < 0 || IsNaN(x):
-		return NaN()
-	case IsInf(x, 1):
-		return 0
-	}
-
-	if n == 0 {
-		return Y0(x)
-	}
-	if x == 0 {
-		if n < 0 && n&1 == 1 {
-			return Inf(1)
-		}
-		return Inf(-1)
-	}
-	sign := false
-	if n < 0 {
-		n = -n
-		if n&1 == 1 {
-			sign = true // sign true if n < 0 && |n| odd
-		}
-	}
-	if n == 1 {
-		if sign {
-			return -Y1(x)
-		}
-		return Y1(x)
-	}
-	var b float64
-	if x >= Two302 { // x > 2**302
-		// (x >> n**2)
-		//	    Jn(x) = cos(x-(2n+1)*pi/4)*sqrt(2/x*pi)
-		//	    Yn(x) = sin(x-(2n+1)*pi/4)*sqrt(2/x*pi)
-		//	    Let s=sin(x), c=cos(x),
-		//		xn=x-(2n+1)*pi/4, sqt2 = sqrt(2),then
-		//
-		//		   n	sin(xn)*sqt2	cos(xn)*sqt2
-		//		----------------------------------
-		//		   0	 s-c		 c+s
-		//		   1	-s-c 		-c+s
-		//		   2	-s+c		-c-s
-		//		   3	 s+c		 c-s
-
-		var temp float64
-		switch n & 3 {
-		case 0:
-			temp = Sin(x) - Cos(x)
-		case 1:
-			temp = -Sin(x) - Cos(x)
-		case 2:
-			temp = -Sin(x) + Cos(x)
-		case 3:
-			temp = Sin(x) + Cos(x)
-		}
-		b = (1 / SqrtPi) * temp / Sqrt(x)
-	} else {
-		a := Y0(x)
-		b = Y1(x)
-		// quit if b is -inf
-		for i := 1; i < n && !IsInf(b, -1); i++ {
-			a, b = b, (float64(i+i)/x)*b-a
-		}
-	}
-	if sign {
-		return -b
-	}
-	return b
-}