出典:Wiktionary
出典:『Wiktionary』 (2026/05/21 21:34 UTC 版)
Argument instances are used to test the validity of argument forms. A valid argument form yields only valid argument instances; an invalid argument form has at least one invalid instance. Substitutions must be uniform: the same variable must be replaced by the same term throughout. e.g. Given the argument form: All A are B; x is A; therefore x is B. An argument instance is: All men are mortal; Socrates is a man; therefore Socrates is mortal.