# Path integral formulation | ðŸ—– nosplit | â†‘ parent "Mathematical formulation of quantum field theory" | 61, 2, 92

This one might actually be understandable! It is what Feymann starts to explain at: Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979).

The difficulty is then proving that the total probability remains at 1, and maybe causality is hard too.

The path integral formulation can be seen as a generalization of the double-slit experiment to infinitely many slits.