def unique_variable(pattern=None, ignore=None):
 if (pattern is not None):
  if is_indvar(pattern.name):
   prefix = u'z'
  elif is_funcvar(pattern.name):
   prefix = u'F'
  elif is_eventvar(pattern.name):
   prefix = u'e0'
  else:
   assert False, u'Cannot generate a unique constant'
 else:
  prefix = u'z'
 v = Variable((u'%s%s' % (prefix, _counter.get())))
 while ((ignore is not None) and (v in ignore)):
  v = Variable((u'%s%s' % (prefix, _counter.get())))
 return v

def unique_variable ( pattern = None , ignore = None ) : if ( pattern is not None ) : if is_indvar ( pattern . name ) : prefix = u'z' elif is_funcvar ( pattern . name ) : prefix = u'F' elif is_eventvar ( pattern . name ) : prefix = u'e0' else : assert False , u'Cannot generate a unique constant' else : prefix = u'z' v = Variable ( ( u'%s%s' % ( prefix , _counter . get ( ) ) ) ) while ( ( ignore is not None ) and ( v in ignore ) ) : v = Variable ( ( u'%s%s' % ( prefix , _counter . get ( ) ) ) ) return v
return a new .