   (save-excursion (goto-char pos) (current-column)))
 
 (defun fstar-subp-send-region (beg end lax)
-  "Send the region between BEG and END to the inferior F* process."
+  "Send the region between BEG and END to the inferior F* process.
+With non-nil LAX, send region in lax mode."
   (interactive "r")
   (fstar-subp-start)
   (let* ((pushlc (concat fstar-subp--header
 			 (format " %d %d"
 				 (line-number-at-pos beg)
 				 (column-number-at-pos beg))))
-	 (header (if (eq lax 0)
-		     pushlc
-		   (concat pushlc " " fstar-subp--laxheader)))
-	 (msg (concat header "\n"
-		      (fstar-subp-prepare-message (buffer-substring-no-properties beg end))
-		      fstar-subp--footer)))
+         (header (if lax
+                     (concat pushlc " " fstar-subp--laxheader)
+                   pushlc))
+         (msg (concat header "\n"
+                      (fstar-subp-prepare-message (buffer-substring-no-properties beg end))
+                      fstar-subp--footer)))
     (fstar-subp-log "QUERY [%s]" msg)
     (process-send-string fstar-subp--process msg)))
 

  (fstar-subp-start)
  (fstar-subp-set-status overlay 'busy)
  (setq fstar-subp--busy-now overlay)
  (fstar-subp-send-region (overlay-start overlay) (overlay-end overlay) (overlay-get overlay 'fstar-subp--lax)))

(defun fstar-subp-process-queue ()
  "Process the next pending overlay, if any."

    (skip-chars-backward "\n\r\t ")
    (point)))

(defun fstar-subp-enqueue-until (end &optional no-error)
  "Mark region up to END busy, and enqueue the newly created overlay.

If NO-ERROR is set, do not report an error if the region is empty."
