The market equilibrium problem has been studied for a long time. Walras, in 1874, introduced a model for economic systems based on supply and demand. In 1936, Wald proved the existence of equilibrium under certain conditions. Arrow and Debreu, in 1954, showed the existence of equilibrium under less strict assumptions. This result, along with the two welfare theorems, forms the basis of modern equilibrium theory. The First Fundamental Theorem of Welfare demonstrates that market prices lead to optimal allocations, supporting the idea of markets working efficiently.