Fix sqrt function (again)

packages/math/math.grnd

@@ -185,6 +185,9 @@ fun -double !sqrt -double &in
     # Finding sqrt(a) is the same as finding the roots of
     # f(x) = x^2 - a
     # Using Newton's method: x_(k+1) = x_k - f(x_k)/f'(x_k) = x_k - ((x_k)^2-a)/2(x_k)
+    lesser $in 0 &store
+    if $store %error
+
     set &ans 2
     @loop
         multiply $ans $ans &num
@@ -193,9 +196,7 @@ fun -double !sqrt -double &in
         multiply $ans 2 &dom
 
         divide $num $dom &store
-        lesser $store 0.00000001 &store2
-        greater $store -0.00000001 &store3
-        equal $store2 $store3 &store2
+        equal $store 0 &store2
         if $store2 %end
 
         subtract $ans $store &ans
@@ -203,8 +204,6 @@ fun -double !sqrt -double &in
 
     @end
     return $ans
-endfun
 
-pusharg 2.25
-call !sqrt &store
-stdlnout $store
+    @error
+endfun