Child axis

# both the same
//ul/li/a
//child::ul/child::li/child::a

child:: is the default axis. This makes //a/b/c work.

# both the same
# this works because `child::li` is truthy 
//ul[li]
//ul[child::li]

# both the same
//ul[count(li) > 2]
//ul[count(child::li) > 2]