Complex sentence: \\ ll 1 (and similarly for all derivatives of h) and that all products (contractions) of h (or its derivatives) with h or it's derivatives are ignored (equivalent to ignoring all terms of higher order than 1 in\\ epsilon).
Split into simpler sentences: \\ ll 1 (and similarly for all derivatives of h). Then one ignores all products of h (or its derivatives) with h or its derivatives (equivalent to ignoring all terms of higher order than 1 in\\ epsilon).