Variables are italicized (e.g., TU, startTimes).
Variable values (e.g., month, date), keywords
(e.g., if, then, else), and conceptual notations
are in bold-face.
Function names are in roman (e.g., merge(TU1, TU2)).
Y refers to the field(s) Y within X
% Denotes comments in rules.
forward-looking-adjective are adjectives that indicate a time
in the future. For instance, ``next'', ``following'', or in Spanish
``proximo'', ``siguiente'', ``viene''.