'Find and return another piece of converted output.'

def __next__(self):

    if (self.pos >= len(self.tex)):
        raise StopIteration
    nextoutput = self.chunk()
    if ((self.lastoutput[0] == '\\') and self.lastoutput[(-1)].isalpha() and nextoutput[0].isalpha()):
        nextoutput = ('    ' + nextoutput)
    self.lastoutput = nextoutput
    return nextoutput
