pretty printer bool expressions

examples/oopsla/absynth/polynomial/trader.pwhile

 def start():
-      var sPrice, minPrice, tick_z, numShares
-
-      tick_z = 0
+      var sPrice, minPrice, numShares
 
       while 0<=minPrice and minPrice<sPrice:
          prob(1,3):
@@ -11,5 +9,4 @@ def start():
          numShares = unif(0,20)
          while numShares>0:
              numShares=numShares-1
-             tick_z=tick_z+sPrice
-      tick(tick_z)
+             tick(sPrice)

examples/oopsla/queueing-network.absynth

+def qn ():
+    var l1, l2, n, i, tick_z
+    l1 = 0
+    l2 = 0
+    i = 0
+    while i <= n:
+        n = n - 1
+        if l1 > 0:
+            l1 = l1 - 1
+        if l2 > 0:
+            l2 = l2 - 1
+
+        prob (1,49):
+            prob(1,4):
+                l1 = l1 + 3
+            else:
+                prob(1,1):
+                    l2 = l2 + 2
+                else:
+                     l1 = l1 + 2
+                     l2 = l2 + 1
+
+        if l1 >= l2:
+            tick_z = l1 + tick_z
+        else:
+            tick_z = l2 + tick_z

examples/oopsla/queueing-network.pwhile

+def qn ():
+    var l1, l2, n, i, tick_z
+    l1 = 0
+    l2 = 0
+    i = 0
+    while i <= n:
+        n = n - 1
+        if l1 > 0:
+            l1 = l1 - 1
+        if l2 > 0:
+            l2 = l2 - 1
+
+        prob (1,49):
+            prob(1,4):
+                l1 = l1 + 3
+            else:
+                prob(1,1):
+                    l2 = l2 + 2
+                else:
+                     l1 = l1 + 2
+                     l2 = l2 + 1
+
+        if l1 >= l2:
+            tick_z = l1 + tick_z
+        else:
+            tick_z = l2 + tick_z

src/Data/PWhile/BoolExpression.hs

@@ -147,10 +147,10 @@ variables g = S.unions [ E.variables a `S.union` E.variables b  | (a :>=: b) <-
 
 instance PP.Pretty p => PP.Pretty (Literal p) where
   pretty (e1 :>=: e2) =
-    PP.nest 2 (PP.group (PP.pretty e1 PP.<$> PP.nest 2 (PP.group (PP.text "≥" PP.<$> PP.pretty e2))))
+    PP.group (PP.pretty e1) PP.</> PP.text "≥" PP.<+> PP.group (PP.pretty e2)
 
 instance PP.Pretty l => PP.Pretty (DNF l) where
   pretty Top = PP.text "⊤"
   pretty Bot = PP.text "⊥"
   pretty dnf = lst " ∨ "  [ lst " ∧ " [ PP.group (PP.pretty l) | l <- lits c] | c <- conjs dnf]
-    where lst s = PP.hcat . PP.punctuate (PP.text s)
+    where lst s = PP.fillSep . PP.punctuate (PP.text s)