Hi, I´m Albrecht Niekamp, Duesseldorf
  Niekamp@online-club.de
  These formulas continue the multifrac.frm
  formula-collection. Here you will find the
  more sophisticated variations of the original
  multifrac13 or multifrac13a formula.
  The formula names correspond to the par-files
  with the same number. 
  Suggestions, new par-files or own variations
  are welcome.
--------------------------------------------------
  multifrac68 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (x2<y2)
  x=x2-y2-p1 
  y=y2-x2-p2
  if (y2<w2)
  w=w2-x2-p3  
  else
  w=w2-y2-p3
  endif
  z=fn1(z+x+y+w)
  else
  x=x2*y2-p1
  y=2*x2*y2-p2
  if (x2<w2)
  w=2*x2*w2-p3
  else
  w=2*y2*w2-p3
  endif
  z=fn2(z-x-y-w)
  endif
  |z| > (x2+w2+y2)
  }
 multifrac69 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (x2<y2)
  x=x2-y2-p1 
  y=y2-x2-p2
  if (y2<w2)
  w=w2-x2-p3  
  else
  w=w2-y2-p3
  endif
  z=fn1(z+x+y+w)
  else
  x=x2*y2+p1
  y=2*x2*y2+p2
  if (x2<w2)
  w=2*x2*w2+p3
  else
  w=2*y2*w2+p3
  endif
  z=fn2(z-x-y-w)
  endif
  |z| > (x2+w2+y2)
  }
 multifrac70 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (x2<y2)
  x=x2-y2-p1 
  y=y2-w2-p2
  if (y2<w2)
  w=w2-x2-p3  
  else
  w=w2-y2-p3
  endif
  z=fn1(z+x+y+w)
  else
  x=x2*y2+p1
  y=2*x2*w2+p2
  if (x2<w2)
  w=2*x2*w2+p3
  else
  w=2*y2*w2+p3
  endif
  z=fn2(z-x-y-w)
  endif
  |z| > (x2+w2+y2)
  }
 multifrac71 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (x2<y2)
  x=x2-y2-p1 
  y=y2-w2-p2
  if (y2<w2)
  w=w2-x2-p3  
  else
  w=w2-y2-p3
  endif
  z=fn1(z+x+y+w)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  if (x2<w2)
  w=x2*w2+p3
  else
  w=y2*w2+p3
  endif
  z=fn2(z-x-y-w)
  endif
  |z| > (x2+w2+y2)
  }
 multifrac72 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (x2>y2)
  x=x2-y2-p1 
  y=y2-w2-p2
  if (y2>w2)
  w=w2-x2-p3  
  else
  w=w2-y2-p3
  endif
  z=fn1(z+x+y+w)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  if (x2>w2)
  w=x2*w2+p3
  else
  w=y2*w2+p3
  endif
  z=fn2(z-x-y-w)
  endif
  |z| > (x2+w2+y2)
  }
 multifrac73 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (x2<y2)
  x=x2-y2-p1 
  y=y2-w2-p2
  if (y2<w2)
  w=w2-x2-p3  
  else
  w=w2-y2-p3
  endif
  z=fn1(z+x+y+w)
  phc_bailout = |z| > (x2*y2*w2)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  if (x2<w2)
  w=x2*w2+p3
  else
  w=y2*w2+p3
  endif
  z=fn2(z-x-y-w)
  phc_bailout = |z| > (x2+y2+w2)
  endif
  phc_bailout
  }
  multifrac74 {
  cr=real(scrnpix)+2*imag(scrnpix)  
  r=cr-4*trunc(cr/real(4))
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (r<2)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  if (r==0)
  w=2*w2-x2-p3  
  else
  w=2*w2-y2-p3
  endif
  z=fn1(z+x+y+w)
  phc_bailout = |z| > (x2*y2*w2)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  if (r==2)
  w=x2*w2+p3
  else
  w=y2*w2+p3
  endif
  z=fn2(z-x-y-w)
  phc_bailout = |z| > (x2+y2+w2)
  endif
  phc_bailout
  }
  multifrac75 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (x2<y2)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-x2-p3 
  z=fn1(z+x+y+w)
  phc_bailout = |z| > (x*y)
  elseif (y2<w2)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-y2-p3  
  z=fn1(z+x+y+w)
  phc_bailout = |z| > (x*w)
  elseif (x2<w2)
  x=x2*y2+p1
  y=x2*w2+p2
  w=x2*w2+p3
  z=fn2(z-x-y-w)
  phc_bailout = |z| > (x+y)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  w=y2*w2+p3
  z=fn2(z-x-y-w)
  phc_bailout = |z| > (x+w)
  endif
  phc_bailout
  }

multifrac76 {
  cr=real(scrnpix)+2*imag(scrnpix)  
  r=cr-4*trunc(cr/real(4))
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (r==0)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-x2-p3 
  z=fn1(z+x+y+w)
  phc_bailout = |z| > (x*y*w)
  elseif (r==1)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-y2-p3  
  z=fn1(z+x+y-w)
  phc_bailout = |z| > ((x*y)/w)
  elseif (r==2)
  x=x2*y2+p1
  y=x2*w2+p2
  w=x2*w2+p3
  z=fn2(z-x-y-w)
  phc_bailout = |z| > (x+y+w)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  w=y2*w2+p3
  z=fn2(z-x-y+w)
  phc_bailout = |z| > (x+y-w)
  endif
  phc_bailout
  }
multifrac77 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (x2<y2)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-x2-p3 
  z=fn1(z+x+y+w)
  ptc_bailout = |z| > (x*y*w)
  elseif (y2<w2)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-y2-p3  
  z=fn2(z+x+y+w)
  ptc_bailout = |z| > (x*w)
  elseif (x2<w2)
  x=x2*y2+p1
  y=x2*w2+p2
  w=x2*w2+p3
  z=fn3(z-x-y-w)
  phc_bailout = |z| > (x+y+w)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  w=y2*w2+p3
  z=fn4(z-x-y-w)
  phc_bailout = |z| > (x+w)
  endif
  phc_bailout
  }
multifrac78 {
  cr=real(scrnpix)+2*imag(scrnpix)  
  r=cr-4*trunc(cr/real(4))
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (r==0)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-x2-p3 
  z=fn1(z+x+y+w)
  ptc_bailout = |z| > (x*y*w)
  elseif (r==1)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-y2-p3  
  z=fn2(z+x+y-w)
  ptc_bailout = |z| > ((x*y)/w)
  elseif (r==2)
  x=x2*y2+p1
  y=x2*w2+p2
  w=x2*w2+p3
  z=fn3(z-x-y-w)
  ptc_bailout = |z| > (x+y+w)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  w=y2*w2+p3
  z=fn4(z-x-y+w)
  ptc_bailout = |z| > (x+y-w)
  endif
  ptc_bailout
  }

 multifrac79 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  w2 = w*w
  if (whitesq)
  if (X2<y2)
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-x2-p3 
  z=fn1(z+x+y+w)
  ptc_bailout = |z| > (x*y*w)
  else
  x=2*x2-y2-p1 
  y=2*y2-w2-p2
  w=2*w2-y2-p3  
  z=fn2(z+x+y-w)
  ptc_bailout = |z| > ((x*y)/w)
  endif
  elseif (x2<w2)
  x=x2*y2+p1
  y=x2*w2+p2
  w=x2*w2+p3
  z=fn3(z-x-y-w)
  ptc_bailout = |z| > (x+y+w)
  else
  x=x2*y2+p1
  y=x2*w2+p2
  w=y2*w2+p3
  z=fn4(z-x-y+w)
  ptc_bailout = |z| > (x+y-w)
  endif
  ptc_bailout
  }

 multifrac80 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  if (whitesq)
  if (X2<y2)
  x=2*x2-y2-p1 
  y=2*y2-x2-p2
  z=fn1(z+x+y)
  ptc_bailout = |z| > (x*y)
  else
  x=2*x2-y2-p1 
  y=2*y2-x2-p2
  z=fn2(z+x-y)
  ptc_bailout = |z| > (x/y)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=x2*y2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2*p1
  y=y2*x2*p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x-y)
  endif
  ptc_bailout
  }
 multifrac81 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  if (whitesq)
  if (X2<y2)
  x=2*x2-y2-p1 
  y=2*y2-x2-p2
  z=fn1(z+x+y)
  phc_bailout = |z| > (x*y)
  else
  x=2*x2-y2-p1 
  y=2*y2-x2-p2
  z=fn2(z+x-y)
  phc_bailout = |z| < (x/y)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=x2*y2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2*p1
  y=y2*x2*p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x-y)
  endif
  ptc_bailout
  }

multifrac82 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  if ((x2*y2)<0)
  if (X2<y2)
  x=2*x2-y2-p1 
  y=2*y2-x2-p2
  z=fn1(z+x+y)
  phc_bailout = |z| > (x*y)
  else
  x=2*x2-y2-p1 
  y=y2*x2-p2
  z=fn2(z+x-y)
  phc_bailout = |z| > (y-x)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=y2-x2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2+p1
  y=x2*y2+p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x-y)
  endif
  ptc_bailout
  }

multifrac83 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  if ((x2*y2)<0)
  if (X2<y2)
  x=2*x2-y2-p1 
  y=2*y2-x2-p2
  z=fn1(z+x+y)
  phc_bailout = |z| > (x*y)
  else
  x=2*x2-y2-p1 
  y=y2*x2-p2
  z=fn2(z+x-y)
  phc_bailout = |z| > (y-x)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=y2-x2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2+p1
  y=x2*y2+p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x-y)
  endif
  ptc_bailout
  }

multifrac84 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  if ((x2*y2)<0)
  if (X2<y2)
  x=2*x2-y2+p1 
  y=2*y2-x2+p2
  z=fn1(z+x+y)
  phc_bailout = |z| > (x-y)
  else
  x=2*x2-y2+p1 
  y=y2*x2-p2
  z=fn2(z+x-y)
  phc_bailout = |z| > (y-x)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=y2-x2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2-p1
  y=x2*y2+p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x*y)
  endif
  ptc_bailout
  }

multifrac85 {
  z = pixel:
  y2 = y*y
  x2 = x*x
  if ((x2*y2)<0)
  if (X2<y2)
  x=2*x2-y2+p1 
  y=2*y2-x2+p2
  z=fn1(z+x+y)
  ptc_bailout = |z| > (x*y)
  else
  x=2*x2-y2+p1 
  y=y2*x2-p2
  z=fn2(z+x-y)
  ptc_bailout = |z| > (y-x)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=y2-x2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2-p1
  y=x2*y2+p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x-y)
  endif
  ptc_bailout
  }
multifrac86 {
  x2=x*x
  y2=y*y
  if ((x2*y2)<0)
  if (x2<y2)
  z = fn1(pixel)
  else
  z=fn2(pixel)
  endif
  elseif (x2<y2)
  z=fn3(pixel)
  else
  z=fn4(pixel)
  endif:
  if ((x2*y2)<0)
  if (X2<y2)
  x=2*x2-y2+p1 
  y=2*y2-x2+p2
  z=fn1(z+x+y)
  phc_bailout = |z| > (x-y)
  else
  x=2*x2-y2+p1 
  y=y2*x2-p2
  z=fn2(z+x-y)
  phc_bailout = |z| > (y-x)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=y2-x2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2-p1
  y=x2*y2+p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x*y)
  endif
  ptc_bailout
  }
multifrac87 {
  x2=x*x
  y2=y*y
  if ((x2*y2)<0)
  if (x2<y2)
  z = fn4(pixel)
  else
  z=fn3(pixel)
  endif
  elseif (x2<y2)
  z=fn2(pixel)
  else
  z=fn1(pixel)
  endif:
  if ((x2*y2)<0)
  if (X2<y2)
  x=2*x2-y2+p1 
  y=2*y2-x2+p2
  z=fn1(z+x+y)
  phc_bailout = |z| > (x-y)
  else
  x=2*x2-y2+p1 
  y=y2*x2-p2
  z=fn2(z+x-y)
  phc_bailout = |z| > (y-x)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=y2-x2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2-p1
  y=x2*y2+p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x*y)
  endif
  ptc_bailout
  }
multifrac88 {
  x2=x*x
  y2=y*y
  if (whitesq)
  if (x2<y2)
  z = fn1(pixel)
  else
  z=fn2(pixel)
  endif
  elseif (x2<y2)
  z=fn3(pixel)
  else
  z=fn4(pixel)
  endif:
  if (whitesq)
  if (X2<y2)
  x=2*x2-y2+p1 
  y=2*y2-x2+p2
  z=fn1(z+x+y)
  phc_bailout = |z| > (x-y)
  else
  x=2*x2-y2+p1 
  y=y2*x2-p2
  z=fn2(z+x-y)
  phc_bailout = |z| > (y-x)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=y2-x2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2-p1
  y=x2*y2+p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x*y)
  endif
  phc_bailout
  }
multifrac89 {
  x2=x*x
  y2=y*y
  if (whitesq)
  if (x2<y2)
  z = pixel
  else
  z=-pixel
  endif
  elseif (x2<y2)
  z=1/pixel
  else
  z=Z/pixel
  endif:
  if (whitesq)
  if (X2<y2)
  x=2*x2-y2+p1 
  y=2*y2-x2+p2
  z=fn1(z+x+y)
  phc_bailout = |z| > (x-y)
  else
  x=2*x2-y2+p1 
  y=y2*x2-p2
  z=fn2(z+x-y)
  phc_bailout = |z| > (y-x)
  endif
  elseif (x2<y2)
  x=x2*y2+p1
  y=y2-x2+p2
  z=fn3(z-x+y)
  ptc_bailout = |z| > (x+y)
  else
  x=x2*y2-p1
  y=x2*y2+p2
  z=fn4(z-x-y)
  ptc_bailout = |z| > (x*y)
  endif
  phc_bailout
  }
multifrac90 {
  x2=x*x
  y2=y*y
  w2=w*w
  if ((x2*y2)<0)
  if (x2<y2)
  z = fn1(pixel)
  else
  z=fn2(pixel)
  endif
  elseif (x2<w2)
  z=fn3(pixel)
  else
  z=fn4(pixel)
  endif:
  if ((x2*y2)<0)
  if (X2<y2)
  x=2*x2-y2+p1 
  y=2*y2-x2+p2
  w=2*w2-x2+p3
  z=fn1(z+x+y+w)
  phc_bailout = |z| > (-x-y-w)
  else
  x=2*x2-y2+p1 
  y=y2*x2-p2
  w=w2*x2-p3
  z=fn2(z+x+y-w)
  phc_bailout = |z| > (-x-y+w)
  endif
  elseif (x2<w2)
  x=x2*y2+p1
  y=y2-x2+p2
  w=w2-x2+p3
  z=fn3(z-x-y-w)
  ptc_bailout = |z| > (x+y+w)
  else
  x=x2*y2-p1
  y=x2*y2+p2
  w=x2*w2+p3
  z=fn4(z-x+y+w)
  ptc_bailout = |z| > (x-y-w)
  endif
  ptc_bailout
  }
multifrac91 {
  x2=x*x
  y2=y*y
  w2=w*w
  if ((x2*y2)<0)
  if (x2<y2)
  z = fn1(pixel)
  else
  z=fn2(pixel)
  endif
  elseif (x2<w2)
  z=fn3(pixel)
  else
  z=fn4(pixel)
  endif:
  if ((x2*y2)<0)
  if (X2<y2)
  x=2*x2-y2+p1 
  y=2*y2-x2+p2
  w=2*w2-x2+p3
  z=fn1(z+x+y+w)
  phc_bailout = |z| > (-x-y-w)
  else
  x=2*x2-y2+p1 
  y=y2*x2-p2
  w=w2*x2-p3
  z=fn2(z+x+y-w)
  phc_bailout = |z| > (-x-y+w)
  endif
  elseif (x2<w2)
  x=x2*y2+p1
  y=2*y2-x2+p2
  w=2*w2-x2+p3
  z=fn3(z-x-y-w)
  ptc_bailout = |z| > (x+y+w)
  else
  x=x2*y2-p1
  y=x2*y2+p2
  w=x2*w2+p3
  z=fn4(z-x+y+w)
  ptc_bailout = |z| > (x-y-w)
  endif
  ptc_bailout
  }