After receiving his PhD he took a position at $\langle$he came to$\rangle$ the University of Texas.
He received his master and PhD degrees from the University of Texas.
In 1987 he went to Delhi University.
He is currently Professor of Mathematics at Texas State University.
This research was initiated when the first author was visiting the University of Alberta in the summer of 2008; the financial support and kind hospitality are gratefully acknowledged.