title: AutoLISP: How to solve no function definition error?
body: <p>Below I have pasted the code from my <code>drawmycoil.lsp</code> file.</p>
  
  <pre><code>(defun drwcoil ()
    (setq helices_center '(0 0)) ; this is the center of the helices
    (setq inner_radius 1e3)      ; 1000 microns
    (setq outer_radius 2.4e3)    ; 2400 microns
    (setq coil_thickness 35)     ; 35 microns
    (setq turns (\ (- outer_radius inner_radius)
                   (* coil_thickness 2))) ; coil_thickness is multiplied by 2 to
                                          ; account for coil spacing
    (while (&lt; inner_radius outer_radius)
      (command "HELIX"
               helices_center
               inner_radius
               (+ inner_radius (* coil_thickness 2))
               "t"
               "1"
               "0") ;draws one helix per iteration
      (setq inner_radius 
            (+ inner_radius (* coil_thickness 2))))) ; increments the inner radius
                                                     ; for the next iteration
  
  (defun c:drawmycoil ()
    (drwcoil)
    (princ))
  </code></pre>
  
  <p>Here's the output of the lisp file after it is loaded and executed:</p>
  
  <pre><code>Command: _appload coil35um_intricate.lsp successfully loaded. 
  
  Command: 
  
  Command:  
  
  Command: drawmycoil  ; 
  error: no function definition: \\\\
  </code></pre>
  
  <p>In spite of having clearly defined my functions, I am unable to make AutoCAD/AutoLISP recognize them. I am using Autodesk Education Master Suite 2011. I saw quite a few tutorial sites and most of them are focused on the LISP part of the functions. I am more focused on making AutoCAD plot my drawing for me through LISP. </p>