| Description: Rule of Modus Ponens.
The postulated inference rule of propositional
calculus. See, e.g., Rule 1 of [Hamilton] p. 73. The rule says, "if
𝜑 is true, and 𝜑 implies 𝜓, then
𝜓
must also be
true". This rule is sometimes called "detachment", since
it detaches
the minor premise from the major premise. "Modus ponens" is
short for
"modus ponendo ponens", a Latin phrase that means "the
mode that by
affirming affirms" - remark in [Sanford] p. 39. This rule is similar to
the rule of modus tollens mto 200.
Note: In some web page displays such as the Statement List, the
symbols "& " and "⇒ " informally indicate the relationship
between the hypotheses and the assertion (conclusion), abbreviating the
English words "and" and "implies". They are not
part of the formal
language. (Contributed by NM, 30-Sep-1992.) |
