F. Trains
An isolated sequence, such as (+ */) , which the
“normal” parsing rules do not resolve to a single part of speech is
called a train, and may be further resolved as described below.
A train of two or three verbs produces
a verb and (by repeated resolution), a verb train of any length also produces a
verb. For example, the trains +-*% and +-*%^ are
equivalent to +(-*%) and +-(*%^).
The production is defined by the following diagrams:
HOOK FORK CAPPED FORK
g g g g g g
/ / / / | |
y h x h f h f h h h
| | | | / / | /
y y y y x y x y y x y
For example, 5(+*-)3 is (5+3)*(5-3).
If f is a cap ([:)
the capped branch simplifies the forks to g h y and g x h y .
The train N g h (a noun followed by two verbs) is equivalent
to N"_ g h .
The ranks of the hook and fork are infinite.
A two-element train of a conjunction with a noun or a verb produces an adverb.
For example, &.> produces an adverb that might be called “each”,
and the adverb bc=:<" might be called “box cells”
because, for example, 0 bc x would box the atoms of x .
Finally, a train of two adverbs produces an adverb, and (by implication) a train of any
number of adverbs also produces an adverb. For example, / is the adverb “insert scan”,
and ~/~ is the “commuted table”. For example:
is=:/ + is 1 2 3 4 5 1 3 6 10 15 ct=: ~/~ - ct 1 2 3 0 1 2 _1 0 1 _2 _1 0