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.
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. 'FL' 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 the multiplication of two numbers.