ive inference can be said to be valid,
depends on the
validity of the corresponding deduction, from Case C=&gt;H and Rule H=&gt;~A to
Fact C=&gt;~A.
And it needs to be remembered that the utility of this deduction, which only
concludes
what has already been observed, is that it reduces the surprise of that
observation.

Deduction of a Fact:

Case:     C =&gt; H ,     In the current situation, it is a holiday.
Rule:     H =&gt; D ,     If it is a holiday, there will be decorations.
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