The tree equivalence of linear recursion schemes

In the paper, a complete system of transformation rules
preserving the tree equivalence and a polynomial-time algorithm
deciding the tree equivalence of linear polyadic recursion
schemes are proposed. The algorithm is formulated as a
sequential transformation process which brings together the
schemes in question. In the last step, the tree equivalence
problem for the given schemes is reduced to a global flow
analysis problem which is solved by an efficient marking
algorithm.