Asko Parpola, reviewing the Farmer, Sproat, and Witzel thesis in 2005, states that their arguments "can be easily controverted". He cites the presence of a large number of rare signs in Chinese and emphasizes that there is "little reason for sign repetition in short seal texts written in an early logo-syllabic script". Revisiting the question in a 2007 lecture, Parpola takes on each of the 10 main arguments of Farmer et al., presenting counterarguments. He states that "even short noun phrases and incomplete sentences qualify as full writing if the script uses the rebus principle to phonetize some of its signs". All these points are rejected in a lengthy paper by Richard Sproat, "Corpora and Statistical Analysis of Non-Linguistic Symbol Systems" (2012).