In 1932 he returned to Iaşi, where he remained for almost 10 years, developing a close relationship with professor Alexandru Myller. He taught the first modern algebra course in Romania, named "Logic and theory of proof", at the University of Iaşi. During that time, he started writing a series of papers based on the works of Jan Łukasiewicz in multi-valued logic. His research in mathematical logic laid the foundation for significant work done afterwards in Romania, as well as Argentina, Yugoslavia, Czechoslovakia, and Hungary. While in Iaşi, he completed research remarkable for the many new ideas and for his way of finding and using new connections between concepts from different areas of mathematics. He was promoted to Full Professor in November 1939.