Fix a bug where some letter signs were not put in the proper places

(ueb) 
eg. \frac{1}{3}e needs a letter sign before e.
Also added this after sub/super scripts to avoid any ambiguity, though
it's probably redundant. Not sure  how it is done in ueb books exactly.

latex_access/ueb.py

@@ -52,7 +52,7 @@ def before (self):
 
         Place anything here to do before we begin ueb translate. Eg. set
         variables etc. Should NOT alter the actual input at all."""
-        self.lastnumber = -1 # keep track of where the last latex number was open i.e. after a digit . or , (for ueb)
+        self.lastnumber = -1 # keep track of where the last latex number # was open i.e. after a digit . or , (for ueb)
 
     def super(self,input,start,rting=()):
         '''Translate  superscripts into UEB.
@@ -65,6 +65,7 @@ def super(self,input,start,rting=()):
                 translation = ";9" + self.translate(arg[0],(rting[0]+arg[2],rting[1]+2))
             else:
                 translation = ";9" + self.translate(arg[0])
+            self.lastnumber = arg[1]
         else:
             if rting != ():
                 translation = ";9<" + self.translate(arg[0],(rting[0]+arg[2],rting[1]+3))+">"
@@ -82,6 +83,7 @@ def sub(self,input,start,rting=()):
                 translation = ";5"+self.translate(arg[0],(rting[0]+arg[2],rting[1]+2))
             else:
                 translation = ";5"+self.translate(arg[0])
+            self.lastnumber = arg[1]
         else:
             if rting != ():
                 translation = ";5<"+self.translate(arg[0],(rting[0]+arg[2],rting[1]+3)) + ">"
@@ -120,7 +122,9 @@ def frac(self,input,start,rting=()):
             for number in denominator[0]: translation+=self.upperNumbers[int(number)]
             if rting != ():
                 for j in range(len(numerator[0])): self.rt.append((rting[1]+j+1,rting[0]+numerator[2]+j))
-                for j in range(len(denominator[0])): self.rt.append((rting[1]+j+2+len(numerator[0]),rting[0]+denominator[2]+j))
+                for j in range(len(denominator[0])):
+                    self.rt.append((rting[1]+j+2+len(numerator[0]),rting[0]+denominator[2]+j))
+            self.lastnumber=denominator[1]
         else: # complex fraction
             self.lastnumber = -1 
             if rting != ():