##### Wikipedia

**FL**

**FL** or variations may refer to:

**FL (complexity)**

In computational complexity theory, the complexity class **FL** is the set of function problems which can be solved by a deterministic Turing machine in a logarithmic amount of memory space. As in the definition of L, the machine reads its input from a read-only tape and writes its output to a write-only tape; the logarithmic space restriction applies only to the read/write working tape.

Loosely speaking, a function problem takes a complicated input and produces a (perhaps equally) complicated output. Function problems are distinguished from decision problems, which produce only Yes or No answers and corresponds to the set ** L** of decision problems which can be solved in deterministic logspace. **FL** is a subset of ** FP**, the set of function problems which can be solved in deterministic polynomial time.

**FL** is known to contain several natural problems, including arithmetic on numbers. Addition, subtraction and multiplication of two numbers are fairly simple, but achieving division is a far deeper problem which was open for decades.

Similarly one may define **FNL**, which has the same relation with NL as FNP has with NP.

**FL (programming language)**

**FL** (short for **F**unction **L**evel) is a programming language created at the IBM Almaden Research Center by John Backus, John Williams, and Edward Wimmers in 1989.

FL was designed as a successor of Backus' earlier FP language, providing specific support for what Backus termed function-level programming.

FL is a dynamically typed strict functional programming language with throw and catch exception semantics much like in ML. Each function has an implicit history argument which is used for doing things like strictly functional input/output (I/O), but is also used for linking to C code. For doing optimization, there exists a type-system which is an extension of Hindley–Milner type inference.

Many of the language’s innovative, arguably important ideas have now been implemented in Kenneth E. Iverson’s J language.

#### Usage examples of "fl".

__Flim__ might look like Thrawn, but he had all the tactical genius of a garbage-pit parasite.

Karl says, tossing the tablet onto the desk where it caroms off a stack of books, "spare me the __flim__ flam nobility, the shtick about the tireless search for truth.

__Flim__ flam's spilling his guts: His Highness has rather an ex tensive operation--child labor in his rice paddies and mines, child prostitution, and a child farm where the healthiest are kept that way until someone can pay for the organ they need.