I see 'fn void main()'. There's probably a good reasson but why the 'fn'? It doesn't really add anything because 'void main()' already communicates it's a function.
The main draw of C (to me) is it's terseness and it's avoidance of 'filler' syntax words.
I admit I didn't (yet) look much further into it, but this first thing jumped out to me and slightly diminished my desire to look further into C3...
It's to remove a syntax ambiguity with c-style function declarations https://en.wikipedia.org/wiki/Most_vexing_parse
The syntax ambiguity adds a lot of complexity to the grammar that makes parsing a lot more complicated than it needs to be.
Sticking `fn` in front fixes a lot of problems.