Construction of Path Integral

2 FEYNMAN S PATH INTEGRAL QUANTUM FORMALISM 4.2.1 CONSTRUCTION OF PATH INTEGRAL 

the elementary quantum evolution amplitude (4.7) is to be evaluated, firstly by reconsidering the eigen-coordinate unitary operator, in the working form 

each obtained working energetic contribution are evaluated separated as for kinetic contribution the inserting of the momentum complete eigen-set 

With relations (4.14) and (4.15) back in Eq. (4.11) the elementary propagator takes the form  

Replacing the elementary quantum amplitude (4.16) back in the global one given by Eq. (4.4), it assumes the form  

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