Handle missing explanation template.
Original description
explain/4 should succeed even if an required explanation template is missing.
Discussion
This is hard, if not impossible to realize. Let's suppose there are two possible traces for irrelevant(F)
: a(F)
and b(F)
. But there is only an explanation template for b
. Then the result would be:
- an explanation using
a
and - an empty explanation.
Or, if only for a
an explanation template is known, we have an empty explanation followed by an explanation using b
. Either way, we have two explanations, one of which is empty. This is no sensible behavior.
Desired behavior
Have a graceful API reply if a requested item is irrelevant but explain/4 cannot produce an explanation. The reply should be (following the current naming convention):
{
"explanations": [],
"further_explanations": false
}