2017-03-21: more info from power-iteration stable

more info from power-iteration

diff --git a/examples/power-iteration.w b/examples/power-iteration.w
--- a/examples/power-iteration.w
+++ b/examples/power-iteration.w
@@ -32,6 +32,31 @@ define : M*v A b
                    . i
                    + 1 j
 
+
+define : normalize-squared v
+     let lp : (norm 0) (idx 0)
+         if {idx >= (length v)}
+             let loop : (res '()) (i 0)
+                if {i >= (length v)}
+                    . res
+                    loop 
+                        cons : / (list-ref v i) : sqrt norm
+                             . res
+                        + 1 i
+             lp
+                 + norm : * (list-ref v idx) (list-ref v idx)
+                 + idx 1
+            
+
+define : î-step elem prev
+    normalize-squared : M*v A prev
+
 define : main args
-    write : M*v A b
+    let lp : (i 0)
+        write : fold î-step b : iota i
+        newline
+        when {i < 10}
+          lp {i + 1}
+            
+    write : normalize-squared : M*v A b
     newline