Precisely Unless
If 
is true precisely unless 
, then implies not- and not- implies . J. H. Conway has suggestedthe term ``Unlesss'' for this state of affairs, by analogy with Iff.
- Lattice Animal
- Lattice Distribution
- Lattice Graph
- Lattice Groups
- Lattice Path
- Lattice Point
- Lattice Reduction
- Lattice Sum
- Lattice Theory
- Latus Rectum
- Laurent Polynomial
- Laurent Series
- Law
- Law of Anomalous Numbers
- Law of Cancellation
- Law of Cosines
- Law of Large Numbers
- Law of Sines
- Law of Small Numbers
- Law of Tangents
- Law of Truly Large Numbers
- Lax-Milgram Theorem
- Lax Pair
- Layer
- Leading Digit Phenomenon