Non-Wiener functional integrals

A study is made of Feynman path integrals and some similar integrals which are used to solve the initial-value problem for the Schrödinger equation. The $S$ matrix and the partition function are found. The relationship between these integrals and operator symbols is found. In particular, it is shown that functional integrals of this kind depend strongly on the adopted approximations of finite multiplicity. The relation between the Feynman integral and the Wick formula is discussed.