目次 Davies (1841) Nagumo (1977) Freudenthal (1983) Vergnaud (1983) Anghileri＆Johnson (1988) Vergnaud (1988) Greer (1992) Shoenfield (2008) Yoshida (2009) Isoda＆Olfos (2009) Nunokawa (2010) Vorderman (2010)