The intention of the authors is to examine the relationship between piecewise linear structure and differential structure: a relationship, they assert, that can be understood as a homotopy obstruction theory, and, hence, can be studied by using the traditional techniques of algebraic topology....

\"Colloquial Polish\" is a practical course in everyday written and spoken Polish requiring no prior knowledge of the language. It is ideal for anyone seeking to develop a sound command of contemporary Polish whether studying independently or with a teacher. The course is designed to encourage you to learn and practise essential language skills....