First version of the growth grammar

[tisztamo]

Should be implemented as a Julia DSL.

A sketch of the basic syntax (definitely not covering everything needed):

Fork and exec (generates a “star” around N):
N => N | x
N => N | N2

N(Level) => N(Level+1) | B when Level <= 4

N => N1 | N2

exec (terminates a chain or “ages” a nonterminal):
N => x
N => N2

"Biologically inspired" means that the grammar is context free (only a single component on the left side) but rule application depends on attributes of that node. (Attribute grammar). Moreover, attribute values are either statically computed for the descendants at rule application or dynamically recalculated based on the activity of the node (or even its context, like the load on node where it is scheduled)