Applied temporary fix from previous commit to definite integral bounds too.

src/node.py

@@ -339,8 +339,14 @@ class ExpressionNode(Node, ExpressionBase):
 
         # Add bounds
         if len(self) > 2:
-            lbnd, ubnd = self[2:]
+            op += self.construct_bounds(*self[2:])
 
+        # int x ^ 2      ->  int x ^ 2 dx
+        # int x + 1      ->  int (x + 1) dx
+        # int_a^b x ^ 2  ->  int_a^b x ^ 2 dx
+        return op + ' ' + operand
+
+    def construct_bounds(self, lbnd, ubnd):
         # FIXME: temporary fix: add parentheses around negated bounds to
         # prevent a syntax error (solving the syntax error is better, but
         # harder)
@@ -354,20 +360,15 @@ class ExpressionNode(Node, ExpressionBase):
         else:
             ubnds = str(ExpressionNode(OP_POW, ubnd))
 
-            op += lbnds + ubnds
-
-        # int x ^ 2      ->  int x ^ 2 dx
-        # int x + 1      ->  int (x + 1) dx
-        # int_a^b x ^ 2  ->  int_a^b x ^ 2 dx
-        return op + ' ' + operand
+        return lbnds + ubnds
 
     def construct_indef_integral(self, children):
         # [x ^ 2]_a^b
         F, lbnd, ubnd = self
-        lbnd = str(ExpressionNode(OP_SUBSCRIPT, lbnd))
-        ubnd = str(ExpressionNode(OP_POW, ubnd))
+        #lbnd = str(ExpressionNode(OP_SUBSCRIPT, lbnd))
+        #ubnd = str(ExpressionNode(OP_POW, ubnd))
 
-        return '[%s]%s%s' % (F, lbnd, ubnd)
+        return '[%s]%s' % (F, self.construct_bounds(lbnd, ubnd))
 
     def construct_function(self, children):
         if self.op == OP_ABS: