Algebraic Factoring algorithm to recognise read-once functions.

A fast polynomial-time algorithm was recently proposed to determine whether a logic function expressed as a unate DNF (disjunctive normal form) can be expressed as a read-once formula where each variable appears no more than once. The paper uses a combinatorial characterisation of read-once formulas to achieve its objective. It is shown that one can use the well-known and more intuitive notion of algebraic factoring to devise a recognition algorithm for read-once formulas of slightly worse complexity than the best known polynomial-time algorithm for this problem