Words and groups

WORDS AND GROUPS DAN SEGAL All Souls College, Oxford, OX1 4AL, ... A group word is an expression w = w(x) = s∏ j=1 x ε(j) i(j) where i(1),...,i(s) ∈ {1,...,k} and ε(j) = ±1 for each j. It's convenient to think of k as a fixed, ...