Use graph theory notation

[make-github-pseudonymous-again]

for ( let u of V(G) )
for ( let [ u , v , w ] of E( G ) )
for ( let [ v , w ] of E( G , u ) )
for ( let v of N( G , u ) )

[make-github-pseudonymous-again]

see https://github.com/aureooms/js-graph-theory-notation