The husk and stray are counted as sub-variants of existing mobs as opposed to entirely new mobs, hence why you are unable to simply type /summon Stray or /summon Husk. There was supposed to be spawn eggs for them, but it seems they were removed either intentionally or by accident in the final release.
Axiomatic method, in logic, a procedure by which an entire system (e.g., a science) is generated in accordance with specified rules by logical deduction from certain basic propositions (axioms or postulates), which in turn are constructed from a few terms taken as primitive.
in the ancient mathematics space was a geometric abstraction of the three dimensional space observed in the everyday life the axiomatic method had been the main research tool since euclid about 300 bc the method of coordinates analytic geometry was adopted by renÃ© descartes in 1637