D O C U M E N T 1 9 8 F E B R U A R Y 1 9 2 6 2 1 5 same as above with the point, hence thus not Born’s and Wiener’s sym- bol D.) Then one can ask: how large does[8] become? (τ is a whole number) This can only be computed by infinite series. In doing so, I make use of the re- lation (Quantum Mech. II, chap. 1, eq. 7)[9] where . The assumption that H is a second-order function of p does not need to be em- ployed. Hence (pardon the lengthy computations!):[10] . Now, . On the right-hand side, can be substituted by , and furthermore, by con- tinual application of the commutation relations, bring the terms with H over to the left-hand side: Therefore, finally, according to Taylor and td dϕ ϕ · = td d eiϕτ) ( f p) ( ϕ ϕf(p) – ⋅ ε ∂p ∂f = ε h 2πi -------- = td d eiϕτ) ( td d iϕτ)n· ( n! ---------------¸ n 0= ∞ ¦ © ¹ ¨ § = td d ϕn) ( ϕϕn · 1– ϕϕϕn · 2– ϕ2ϕϕn · 3– … ϕn 1– ϕ · + + + + = ϕ · ∂p ∂H d dt ----(ϕn) - ∂H ∂p ------ϕn - 1– ϕ------ϕn ∂H ∂p - 2– ϕ2------ ∂H ∂p -ϕn 3– …ϕn 1– ∂H ∂p ------ - + + + = = ∂H ∂p ------ -ϕn 1– ∂H ∂p ------ -ϕn 1– ε---------ϕn ∂2H ∂p2 - 2– ∂H ∂p ------ -ϕn 1– 2ε---------ϕn ∂2H ∂p2 - 2– ε2---------ϕn ∂3H ∂p3 - 3– … + + –+ –+ = n-------ϕn ∂H ∂p 1– ε------------------- n n 1– ( )∂2H 2! ----------ϕn ∂p2 - 2– ε2------------------------------------ n n 1– ( )( n 2– )∂3H 3! ----------ϕn ∂p3 - 3– … + + – = td d eiϕτ) ( td d iϕτ)n ( n! --------------- n 0= ∞ ¦ i ∂p ∂H τ iϕτ)n ( 1– n 1– ( )! ---------------------- i 1----------(εi)τ2 2! ---- ∂2H ∂p2 - iϕτ)2 ( n 2– ( )! ------------------ … + n 2= ∞ ¦ – n 1= ∞ ¦ = = i 1 εi ---- H p) ( H p τiε))eiϕτ – ( – ( =