diff --git a/networks.rkt b/networks.rkt
index eeb3452..f9ff6dc 100644
--- a/networks.rkt
+++ b/networks.rkt
@@ -88,6 +88,9 @@
                [lists->tbfs/state (->* ((listof (listof (or/c number? symbol?))))
                                        (#:headers boolean?)
                                        (listof tbf/state?))]
+               [lists->sbfs/state (->* ((listof (listof (or/c number? symbol?))))
+                                       (#:headers boolean?)
+                                       (listof sbf/state?))]
                [read-org-tbfs/state (->* (string?) (#:headers boolean?) (listof tbf/state?))]
                [print-org-tbfs/state (->* ((non-empty-listof tbf/state?)) (#:headers boolean?)
                                           (listof (listof (or/c number? symbol?))))]
@@ -1054,6 +1057,33 @@
                    (tbf/state '#hash((a . 1) (b . 2)) 3)
                    (tbf/state '#hash((a . 1) (b . 1)) 2)))))
 
+;;; Like lists->tbfs/state, but does not expect thresholds in the
+;;; input.
+;;;
+;;; Every lists in the list contains the weights of the SBF.  If
+;;; headers is #t, the names of the variables to appear as the inputs
+;;; of the TBF are taken from the first list.
+;;;
+;;; If headers is #f, the names of the variables are generated as xi,
+;;; where i is the index of the variable.
+(define (lists->sbfs/state lsts #:headers [headers #t])
+  (define rows (if headers (cdr lsts) lsts))
+  (define rows-θ (for/list ([lst (in-list rows)]) (append lst '(0))))
+  (lists->tbfs/state (if headers (cons (car lsts) rows-θ) rows-θ)
+                     #:headers headers))
+
+(module+ test
+  (test-case "lists->sbfs/state"
+    (define tbfs '((1 2) (1 -1)))
+    (check-equal? (lists->sbfs/state tbfs #:headers #f)
+                  (list
+                   (tbf/state '#hash((x0 . 1) (x1 . 2)) 0)
+                   (tbf/state '#hash((x0 . 1) (x1 . -1)) 0)))
+    (check-equal? (lists->sbfs/state (cons '(a b) tbfs) #:headers #t)
+                  (list
+                   (tbf/state '#hash((a . 1) (b . 2)) 0)
+                   (tbf/state '#hash((a . 1) (b . -1)) 0)))))
+
 ;;; Reads a list of tbf/state from an Org-mode string containing a
 ;;; sexp, containing a list of lists of numbers.  As in
 ;;; lists->tbfs/state, the last element of each list is taken to be