# basics
eps ::= ""
eof ::= end-of-file

# some tokens
wordspace ::= ??? [ \t\n] | "\r\n", with newline count <= 1
breakspace ::= ??? [ \t\n] | "\r\n", with newline count >= 2
whitespace ::= wordspace | breakspace
word ::= ??? anything else

# horizontal elements
helem ::= wordspace | word | hlist
hlist ::= eps | helem | helem hlist

# vertical elements
paragraph ::= helem
velem ::= paragraph | vlist
vlist ::= eps | velem | velem breakspace vlist

# top level
file ::= velem

