Definition of postulationally in English:
postulationally
adverb ˌpɒstjʊˈleɪʃ(ə)n(ə)liˌpɒstʃʊˈleɪʃ(ə)n(ə)li
In a postulational manner; by postulation; axiomatically.
Origin
Early 20th century; earliest use found in American Journal of Mathematics. From postulational + -ly.