This example generates a list of basic event models. Basic event models are
used with fault trees to model the reliability of systems. Basic event models
use probability distributions to model the failure characteristics of the
components of the system. For example:

  id_1 distribution = constant probability = 0.5
    coverage = 0.99 restoration = 0 single_point_failure = 0.01 dormancy = 0 ;

states that component id_1 fails at a constant probability of 0.5. Its
coverage model states that when it fails, it has a 1% chance of causing the
entire system to fail through a single point failure. When used as a dormant
spare, it does not fail.

In this example, note how we have to carefully choose values for reals, since
there is a constraint that the three coverage values must sum to 1.

Run it with:

$ yagg -m -u user_code basic_event_model.yg basic_event_model.lg
$ ./output/progs/generate 41