«إن كان زيد إنسانا كان حيوانا»
If Zayd is human, he is an animal.
The antecedent and consequent are present, but no explicit expression such as “every time” or “in some cases” quantifies the conditional judgment. In that respect the statement is indefinite (muhmala).
Indefinite does not mean meaningless or false. It means that the quantity has not been expressly stated. The essential truth of the humanity–animality link and the presence of an explicit quantifier are separate matters.