s35.
Frans H. van Eemeren and Rob Grootendorst (1992), Argumentation, Communication and Fallacies, pp 162 and 215; Christopher Tindale (2007), Fallacies and Argument Appraisal, pp 185–189. For vague logic / fuzzy logic, see Bart Kosko (1993), Fuzzy Thinking; Roy Sorensen (2001), Vagueness and Contradiction. William Empson, footnote to “Bacchus”, in (1955), Collected Poems.