https://**en.wikipedia.org**/wiki/**If_and_only_if**

In logic and related fields such as mathematics and philosophy, **if and only if** (shortened **iff**) is a **biconditional** logical connective between statements.

www.mathwords.com/i/**if_and_only_if**.htm

**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 ...

**www.regentsprep.org**/Regents/math/geometry/GP1/bicon.htm

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

zimmer.csufresno.edu/~larryc/proofs/proofs.**ifandonlyif**.html

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.

www.math.hawaii.edu/~ramsey/Logic/**Iff**.html

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 ...

https://**en.wikipedia.org**/wiki/**Logical_biconditional**

In logic and mathematics, the **logical biconditional** (sometimes known as the material **biconditional**) is the logical connective of two statements asserting "p if and ...

mathworld.wolfram.com/**Iff**.html

**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 .

www.**ifandonlyif**journal.com/**submissions**

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 ...

www-cs-students.stanford.edu/~csilvers/proof/node4.html

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 ...

www.**ifandonlyif**journal.com

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 ...