Compose several predicates - can see this as intersection

A sequence of each year, or month, or week, etc.
Used for 'this year', 'next month', 'last week'..

Builds a sequence of intervals, each starting at the start of pred-from
and ending at the start (inclusive-to? false) or end (inclusive-to? true)
of the first pred-from time that follows the start of pred-from.
Example: (intervals (day-of-week 1) (day-of-week 3) true)

Applies f to each interval yielded by pred.
As f changes intervals, an interval that was ahead can become behind, and
reciprocally. We make the assumption that f doesn't change the order of
intervals though, or it would be much harder to maintain lazyness.

Shifts base-pred forward or backward ('two days after pred')
Duration can be negative ('three hours before pred').
The resulting grain is the one just below the duration's grain
Shifted slots' width is exactly their grain

Takes n cycles of pred. Used for 'next 2 weeks' for instance.
Goes forward for positive n, backward otherwise.

Accepts a :not-immediate option like take-the-nth

Takes the *last* occurence of cyclic-pred *within* base-pred.
For example, cyclic-pred is 'Monday' and base-pred 'October'

Builds a predicate with only the nth time slot of a presumably cyclical pred after ref-time,
backward (negative n) or forward (positive n).
Beware that 0 => first forward, but -1 => first backward

Options:

:not-immediate: if true, the first slot will be dropped if it
contains t. No effect on backward lookups (t is never containes in them).

Like take-the-nth, but takes the nth cyclic-pred *after base-pred*
(or before if n is negative.
Since pred generates sequences, it also generates sequences.

Options: :not-immediate works as usual