A note on tree isomorphisms
نویسندگان
چکیده
منابع مشابه
A Note on Isomorphisms Between Canonical Frames
This paper looks at the question of what kinds of automorphisms and isomorphisms can exist within and between canonical frames for modal logics. Specifically, this paper is able to partially answer the question posed by the author in [7] of whether FL ! = FL !1 in the presence of the extra-ZFC axiom “2! = 2!1 .” We answer the question in the negative for all logics below S5 and for all logics s...
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We show that for k ≥ 5 and the permutations τk = (k − 1)k(k − 2) . . . 312 and Jk = k(k − 1) . . . 21, the generating tree for involutions avoiding the pattern τk is isomorphic to the generating tree for involutions avoiding the pattern Jk. This implies a family of Wilf equivalences for pattern avoidance by involutions; at least the first member of this family cannot follow from any type of pre...
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ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series B
سال: 1974
ISSN: 0095-8956
DOI: 10.1016/0095-8956(74)90064-1