Particle Syntax is a syntax-free syntax for splitting files into particles (separated by line breaks) which can have atoms (separated by spaces) and subparticles (indented lines).
Every line is a particle and every particle is one line.
Newlines separate particles.
The atoms in a particle are separated by a single space.
An indent of +1 space makes a particle a subparticle of the parent line.
Particles has no syntax errors; every document is a valid Particles document.