  We analyse the use of wavelet transform in quantum field theory models
written in light-front coordinates. In a recent paper [W.N Polyzou, Phys. Rev.
D 101(2020) 096004] W.N.Polyzou used $x^+$ variable as 'time', and applied
wavelet transform to the 'spatial' coordinates only. This makes the theory
asymmetric with respect to space and time coordinates. In present paper we
generalise the concept of continuous causal path, which is the basis of path
integration, to the sequences of causally ordered spacetime regions, and
present evaluation rules for Feynman path integrals over such sequences in
terms of wavelet transform. Both the path integrals and the wavelet transform
in our model are symmetric with respect to the light-front variables
($x^+,x^-$). The definition of a spacetime event in our generalization is very
much like the definition of event in probability theory.
