diff --git a/mes.c b/mes.c
index c2b83d46..31a86416 100644
--- a/mes.c
+++ b/mes.c
@@ -971,35 +971,60 @@ less_p (scm *a, scm *b)
 }
 
 scm *
-minus (scm *a, scm *b)
+minus (scm *x/*...*/)
 {
+  scm *a = car (x);
   assert (a->type == NUMBER);
-  assert (b->type == NUMBER);
-  return make_number (a->value - b->value);
+  int n = a->value;
+  x = cdr (x);
+  if (x == &scm_nil)
+    n = -n;
+  while (x != &scm_nil)
+    {
+      assert (x->car->type == NUMBER);
+      n -= x->car->value;
+      x = cdr (x);
+    }
+  return make_number (n);
 }
 
 scm *
-plus (scm *a, scm *b)
+plus (scm *x/*...*/)
 {
-  assert (a->type == NUMBER);
-  assert (b->type == NUMBER);
-  return make_number (a->value + b->value);
+  int n = 0;
+  while (x != &scm_nil)
+    {
+      assert (x->car->type == NUMBER);
+      n += x->car->value;
+      x = cdr (x);
+    }
+  return make_number (n);
 }
 
 scm *
-divide (scm *a, scm *b)
+divide (scm *x/*...*/)
 {
-  assert (a->type == NUMBER);
-  assert (b->type == NUMBER);
-  return make_number (a->value / b->value);
+  int n = 1;
+  while (x != &scm_nil)
+    {
+      assert (x->car->type == NUMBER);
+      n /= x->car->value;
+      x = cdr (x);
+    }
+  return make_number (n);
 }
 
 scm *
-multiply (scm *a, scm *b)
+multiply (scm *x/*...*/)
 {
-  assert (a->type == NUMBER);
-  assert (b->type == NUMBER);
-  return make_number (a->value * b->value);
+  int n = 1;
+  while (x != &scm_nil)
+    {
+      assert (x->car->type == NUMBER);
+      n *= x->car->value;
+      x = cdr (x);
+    }
+  return make_number (n);
 }
 
 scm *
diff --git a/scm.mes b/scm.mes
index edbc993b..73f28a8b 100755
--- a/scm.mes
+++ b/scm.mes
@@ -33,8 +33,6 @@
         (#t (memq x (cdr lst)))))
 (define memv memq)
 
-(define (+ x y) (- x (- 0 y)))
-
 (define-macro (and x y)
   (cond (x y)
         (#t #f)))
diff --git a/test.mes b/test.mes
index 8e2ff1fb..5d004d64 100644
--- a/test.mes
+++ b/test.mes
@@ -238,6 +238,10 @@
 (display (memq 'd '(a b c)))
 (newline)
 
+(display "plus: ")
+(display (+ 1 1 1 1))
+(newline)
+
 (cond ((defined? 'loop2)
        (display "mes:values broken after loop2")
        (newline))
@@ -250,7 +254,7 @@
        (display "call-with-values ==> 6: ")
        (display
         (call-with-values (lambda () (values 1 2 3))
-          (lambda (a b c) (+ (+ a b) c))))
+          (lambda (a b c) (+ a b c))))
        (newline)
        (display "call-with-values ==> 1: ")
        (display ((lambda (x) x) (values 1 2 3)))