new experiments

examples/oopsla/trader-N.pwhile

-# Variation of linear/trader.imp
-
-def trader():
-    var price, min, nShares, maxShares
-    while price > min and min >= 0:
-        prob (1,3):
-            price = price + 1
-        else:
-            price = price - 1
-
-        nShares = rand(maxShares)
-
-        while nShares > 0:
-             nShares = nShares - 1
-             tick price