In logic and related fields such as mathematics and philosophy, if and only if (shortened iff) is a biconditional logical connective between statements.
iff if and only if Biconditional A way of writing two conditionals at once: both a conditional and its converse. For example, the statement "A ...
A biconditional is read as "[some fact] if and only if [another fact]" and is true when the truth values of both facts are exactly the same
Sometimes you can prove an "If, and Only If" assertion without explicitly dividng the proof into two parts. The next example illustrates how this might be done.
Some Uses of "if and only if" in Writing About Mathematics . Theorems which have the form "P if and only Q" are much prized in mathematics. They give what are called ...
In logic and mathematics, the logical biconditional (sometimes known as the material biconditional) is the logical connective of two statements asserting "p if and ...
Iff. If and only if (i.e., necessary and sufficient). The terms "just if" or "exactly when" are sometimes used instead. iff is written symbolically as , , , or .
We are currently accepting submissions for our cover design contest. General submissions will reopen on Dec 1, 2015. General Guidelines. Poetry (up to 5 poems) and ...
The term ``if and only if'' is really a code word for equivalence. To prove a theorem of this form, you must prove that A and B are equivalent; that is, not only is B ...
Disappearing Acts. by Luís Galvão. Like so many family stories, this one starts at the dinner table. My father’s not home, he’s at some political meeting, rally ...