Original sentence: End of the Line.For example, any integer has a prime factorization, but computing such a factorization is potentially difficult.Formally speaking, TFNP is the class of function problems in FNP that are guaranteed to be total.It has attracted significant attention in algorithmic game theory in recent years because it contains the problem of computing a Nash equilibrium, and this problem was recently shown to be complete for the class.PPAD is a subset of a so-called semantically defined class known as TFNP.Unlike NP, which is formally concerned with deciding if a solution exists to a given problem (such as whether there is a satisfying assignment in a 3-SAT formula), TFNP refers to those problems for which a solution is always known to exist, but for which actually constructing such a solution may be computationally difficult
Edited sentence: PPAD is a subset of the class TFNP, the class of function problems in FNP that are guaranteed to be total.The class attracted significant attention in the field of algorithmic game theory because it contains the problem of computing a Nash equilibrium, and this problem was shown by Cheni and Deng in 2005 to be complete for the class