Set the BASE attribute of the numth node to "true" or "false".
The base attribute is equivalent to using setbase. But setbase lets you access any element in the rhs phrase of a rule.
_np [base] <- _noun @@
This example and the one below "hide" the _noun node and any node under it, so that subsequent rules such as
_np <- _det [opt s] _noun [s] @@
won't find a singleton _noun that has already been reduced to an _np.
single(); # Need to put the default reduce in manually, since POST is not empty.
_np <- _noun @@
setunsealed, POST Actions